I have an access front-end that connects to SQL Server tables and works fine. When I compile it into an accde file however, I get various errors when closing the DB. The errors seem to indicate that the program is still looking for a table or the value of a global variable. There is a routine in the Form_Close() event of a hidden form that Deletes all the links to the SQL Server back-end. So, how can I debug an already compiled access database? Why does the compiled DB behave differently than the uncompiled (accdb) version?
You need to trap errors using On error goto LabelName or if you don't care about errors you should use On error resume next on top of your code. You should still post your code to get more accurate help.
Are you talking about the same computer, or different computer?
The compiled accDE are VERY sensitive to being executed on a different machine (even the same version). The reason for this is that the compiled accDE takes on your current office release version.
In terms of global variables, and error handling?
accDE's are the BEST choice, since un-handled errors does not re-set local, or even global variables. In effect, a accDE runs like a un-stoppable freight train.
if your accDB (un-compiled) works and runs fine on your computer, then I have NEVER seen a case in which the accDE does not run, and in fact run better and behavies far more ro-bust.
So, no, you can't debug the accDE, but you can the accDB on the SAME computer.
If you are running the accDE on a different computer, then you left out a massive, huge and SPECTUALAR bit of information in your post.
If you ARE running the accDE on the same computer (that you created it with), then about the only possible is that the accDE file extension is using a different version of access to run with. This is rare - I would thus from the control panel, applications and features find your version of access and right click and do a repair on your office install.
The issue of patch version of office/access is VERY significant here. The reason of course is that if you deploy the accDB, it will often work because access can (and does) detect that the current version (even SP/patch/update) level of Access is different, then it can re-compile the code on the fly (because the accDB has the source code). The accDE does not, and thus it can't re-compile. However, I still STRONG suggest you deploy the accDE and resolve the SP/patch level issue since a accDE is oh so much more reliable in its operations compared to un-compiled accDB's.
I would be rather stunned if you are experiencing this issue on the same computer running the accDB and that computer is then used to create the accDE. If this is the actual case, then I would create a new blank accDB, and import everything from the old accDB, and then ensure it can compile the code (from IDE debug->compile). If the app compiles, then create the accDE, and it should work just fine. So, if this is same machine, then your accDB is damaged or corrupted. As I stated, create a new one, import everything from old, and create your accDE from that. It will work, and I never seen a case in which a accDB works, and a accDE does not work (on same machine).
1st thing to do is to decompile your application ...just Google Ms Access Decompile.
When you perform the Decompile and try to compile is almost certain that you will find some "forgotten" mistakes.
2nd if 1st fails its time to implement a robust logging system...based on text file writing, in order to avoid dependencies just work low : https://learn.microsoft.com/en-us/office/vba/language/reference/user-interface-help/freefile-function.
If it still fails post back with more info.
Related
I have a solution written in VB with some C# components. The solution uses some libraries from 2 outside sources. I have been working on this project for several months without issue. I cannot identify anything specific that I did to change my system or configuration. I was just working through the code, transitioning from an old set of library calls to the new library calls. The new library calls require complete rewrite so I change sections of the code and test to that point. Visual Studio 2013 debugger as of Friday morning will no longer recognize or show my local variables in this solution. The only things that appear in the Locals window are under Me. The code does work and I have it writing out to a text log file to confirm the values of variables at certain points, but the debugger has gone blind. When I add any of these local variables to Watch the response is " is not declared. It may be inaccessible due to its protection level."
Steps I've taken so far with no permanent success:
looked online and tried the few matches I found with no success
deleted the bin and obj folders and had the solution rebuild with no
success
recreated solution from scratch, copied over base files and rebuilt
solution and project (which worked for a few hours), until I did a
rebuild project and problem appeared again
updated to pack 5 and no success
I have opened my older projects and checked them. The debugger runs just fine and shows the variables. It is obviously something that happens during the rebuild process.
Any assistance would be greatly appreciated.
Thanks
Update:
Let me try to explain a little more clearly the situation.
I have an application I have built and am selling to some customers. Version 1 is installed and running at several locations. It is written in VB and uses some older COM libraries for a particular integration process.
The vendor is retiring the COM libraries. Their new libraries are in C#.
I created a new copy of my entire application (solution) and imported the new C# libraries. I have been going through and replacing the old code with the code for the new calls.I recompiled the solution and everything ran fine in debug.
The objects used with the new calls are completely different and there is limited documentation so I update a section of code and test to that point. Each time I "Save all Files", rebuild the project and test the changes. Everything worked fine for a few days. On Friday morning I started working on more changes and got an odd error. The system was not getting a proper value for a certain variable. When I went to check it in the WATCH window, debugger said it could not evaluate it. I figured something was hung up so I shut everything down and rebooted my machine. When I tried it again later, the same problem.
After several hours of no success I exited VS, renamed the folder to "OLD" and recreated the solution from the older version. Immediately everything was looking fine. I started making the changes and testing. Each time I did a rebuild, everything looked fine until the last change. Here I am again.
The code works fine up to the point I have updated. The only issue is that the debugger windows are not working correctly. If a variable is declared at the Class level outside the Sub, they can be seen. The only variables the debugger is blind to are the local variables within the running Sub.
I looked for anyone else with this issue and only found a few items. I tried the suggestions but no joy. I am left with having to temporarily define the variables outside the sub so I can see them while debugging.
I am on VS 2013 Update 5.
Do I need to move to VS 2015 to get around this?
Thanks again for your time and assistance.
I am assuming that you haven't changed versions of visual studio since the last time a rebuild worked for you.
recreated solution from scratch, copied over base files and rebuilt solution and project (which worked for a few hours), until I did a rebuild project and problem appeared again
Based on this, you create it from scratch and everything works until you do the rebuild right? But you are copying the base files still and you have new library calls since the last time a rebuild didn't mess up the locals window. So one of those is almost assuredly the culprit.
Since the library calls seem to be the thing that changed based on your post start there. If you go back to the old code and do a rebuild does it fix it? Assuming so, put the library calls back one at a time until it breaks.
If going back to the old code doesn't fix it, create from scratch with the old code and copy over the base files and rebuild. If that fixes it, add new library calls one at a time and rebuild after each until it breaks.
If that doesn't fix it either, then you will need to dig deeper on what else might have changed.
You are copying base files so eliminate those as the problem if you can:
Are you able to use placeholders instead of the base files or something that won't necessarily work as a finished product but that will allow you to debug, rebuild, debug again to see if the problem is related to one of them? Check the dates on the base files and ensure that they haven't changed since the last time a rebuild worked.
Something you could do concurrently could be to have have a colleague do a rebuild on their machine and see if the same issue comes up for them. It would (almost) completely eliminate the possibility that it is a configuration / program corruption issue on yours. Alternately, there are some free vb.net compilers online that you can upload files and code to. I'm not sure if that would be practical for you (due to the components of your program and/or sensitivity of the data) or not and haven't ever tried any where there is C# code in there but I wouldn't think that would be an issue.
I am working with visual studio 2012, and my problem occurs in a large, old winforms application solution when I try to compile the whole application (dozens of projects).
When I get the latest code from source control (Team Foundation Server) for the first time, and build the solution, it builds just fine the first time. Then, if I make any changes, a later Build/Rebuild, will sometimes (not always) result in lots of projects in the solution throwing the following error for some of its resx files.
Unable to create a manifest resource name for "Contracts\Templates\ContractTemplateDb.resx". Could not find a part of the path 'C:\Windows\system32\Contracts\Templates\ContractTemplateDb.vb'
OR
Invalid Resx file. Could not find a part of the path 'C:\Windows\system32\NeptuneForms\HelpForm.resx'.
The problem is that there is no reason it should be looking in C:\Windows\system32 for these files, as they exist fine (and did during the last build) in the local directory of the project! The random directory is not always C:\Windows\system32, sometimes it is a random directory of another project, or even in another branch.
This happens sporadically to some of our developers, frequently to others, and almost always to me, and it seems unrelated to the code we are writing, because when it happened, I rolled back all the changes we had made since it started happening, and it still happened.
There are two things I've tried, that had no success.
Recreate the entire solution, and remove and readd all resource files as though they never existed before.
Install all windows updates and get the latest updates to Visual Studio 2012
Nothing has helped, and I am at a loss. My next step is to upgrade to 2013 and hope for the best, but I'm afraid thats not going to help either.
Does anyone have any similar experience, or any ideas of other things to try? I'm pulling my hair out over this one...
My firm's Access database has been having some serious problems recently. The errors we're getting seem like they indicate corruption -- here are the most common:
Error accessing file. Network connection may have been lost.
There was an error compiling this function.
No error, Access just crashes completely.
I've noticed that these errors only happen with a compiled database. If I decompile it, it works fine. If I take an uncompiled database and compile it, it works fine -- until the next time I try to open it. It appears that compiling the database into a .ACCDE file solves the problem, which is what I've been doing, but one person has reported that the issue returned for her, which has me very nervous.
I've tried exporting all of the objects in the database to text, starting with a brand new database, and importing them all again, but that doesn't solve the problem. Once I import all of the objects into the clean database, the problem comes back.
One last point that seems be related, but I don't understand how. The problem started right around the time that I added some class modules to the database. These class modules use the VBA Implements keyword, in an effort to clean up my code by introducing some polymorphism. I don't know why this would cause the problem, but the timing seems to indicate a relationship.
I've been searching for an explanation, but haven't found one yet. Does anyone have any suggestions?
EDIT: The database includes a few references in addition to the standard ones:
Microsoft ActiveX Data Objects 2.8
Microsoft Office 12.0
Microsoft Scripting Runtime
Microsoft VBScript Regular Expressions 5.5
Some of the things I do and use when debugging Access:
Test my app in a number of VM. You can use HyperV on Win8, VMWare or VirtualBox to set up various controlled test environments, like testing on WinXP, Win7, Win8, 32bit or 64 bits, just anything that matches the range of OS and bitness of your users.
I use vbWatchDog, a clever utility that only adds a few classes to your application (no external dependency) and allows you to trap errors at high level, and show you exactly where they happen. This is invaluable to catch and record strange errors, especially in the field.
If the issue appears isolated to one or a few users only, I would try to find out what is special about their config. If nothing seems out of place, I would completely unsintall all Office component and re-install it after scrubbing the registry for dangling keys and removing all traces of folders from the old install.
If your users do not need a complete version of Access, just use the free Access Runtime on their machine.
Make sure that you are using consistent versions of Access throughout: if you are using Access 2007, make sure your dev machine is also using that version and that all other users are also only using that version and that no components from Access 2010/2013 are present.
Try to ascertain if the crash is always happening around the same user-actions. I use a simple log file that I write to when a debugging flag is set. The log file is a simple text file that I open/write to/close everytime I log something (I don't keep it open to make sure the data is flushed to the file, otherwise when Access crashes, you may only have old data in the log file as the new one may still be in the buffer). Things I log are, for instance, sensitive function entry/exit, SQL queries that I execute from code, form open/close, etc.
As a generality, make sure your app compiles without issue (I mean when doing Debug > Compile from the IDE). Any issue at this stage must be solved.
Make absolutely sure you close all open recordsets, preferrably followed by setting their variables to Nothing. VBA is not as sensitive as it used to be about dangling references, but I found it good practice, especially when you cannot be absolutely sure that these references will be freed (especially when doing stuff at Module-level or Class-level for instance, where the scope may be longer-lived than expected).
Similarly, make sure you properly destroy any COM object you create in your classes (and subs/functions. The Class_Terminate destructor must explicitly clean up all. This is also valid when closing forms if you created COM objects (you mentioned using ADOX, scripting objects and regex). In general keeping track of created objects is paramount: make sure you explicitly free all your objects by resetting them (for instance using RemoveAll on a dictionary, then assigning their reference to Nothing.
Do not over-use On Error Resume or On Error Goto. I almost never use these except when absolutely necessary to recover from otherwise undetectable errors. Using these error trapping constructs can hide a lot of errors that would otherwise show you that something is wrong with your code. I prefer to program defensively than having to handle exceptions.
For testing, disable your error trapping to see if it isn't hiding the cause of your crashes.
Make sure that the front-end is local to the user machine, You mention they get their individual front-end from the network but I'm not sure if they run it from there or if it it copied on their local machine. At any rate, it should be local not on a remote folder.
You mention using SQL Server as a backend. Try to trace all the queries being executed. It's possible that the issue comes from communication with SQL Server, a corrupt driver, a security issue that prevents some queries from being run, a query returning unexpected data, etc. Watch the log files and event log on the server closely for strange errors, especially if they involve security.
Speaking of event log, look for the trace of the crash in the event log of your users. There may be information there, however cryptic.
If you use custom ribbon actions, make sure thy are not causing issues. I had strange problems over time with the ribbon. Log all all function calls made by the ribbon.
I'm seeing a strange build bug a lot. Sometimes after typing some code we receive the following build error.
Class 'clsX' must implement 'Event PropertyChanged(sender As Object, e As PropertyChangedEventArgs)' for interface System.ComponentModel.INotifyPropertyChanged'.
And
'PropertyChanged' cannot implement 'PropertyChanged' because there is no matching event on interface 'System.ComponentModel.INotifyPropertyChanged'.
Those error should never go together! Usually we can just ignore the exception and build the solution but often enough this bug stops our build. (this happens a lot using Edit and Continue which is annoying)
We're using Vb.net and c# mixed in one big solution.
Removing the PropertyChanged event and retyping the same code! sometimes fixes this.
Question:
Has anyone else seen this problem and has some suggestions how to prevent his?
We're using a code generator that causes this error to surface but just editing some files manually triggers this exception too. This error occur's on multiple machines using various setups.
Someone had the same exact issue discussed here. It sounds like there is an issue with this build picking up an old version of a binary. I would try the following in order:
Verify all assembly references use project references where possible within the Visual Studio solution.
Disable build parallelization in case there is some weird file locking issue with concurrent project builds. Go to Tools -> Options, Projects and Solutions -> Build and Run, then set "maximum number of parrellel project builds" to 1. Not the best solution but it may help narrow down the problem.
Disable the Hosting Process in case it's locking some file causing an assembly to not get rebuilt correctly. For C# project go to Project Properties, Debug tab, and uncheck "Enable the Visual Studio hosting process". For VB.NET project you'll need to Unload Project, Edit the project file, and add <UseVSHostingProcess>false</UseVSHostingProcess> to the PropertyGroup of each configuration. Again, not the best solution but you probably won't notice a difference.
Lastly, try doing a Clean + Build to try and resolve the issue when it occurs (I know this is not a fix but it's easy enough to do), also Rebuild may be slightly different than Clean + Build so try the latter if the former doesn't work.
As I can not comment due to lack of appropriate points.
But I would like to share one of my experience:
In an aspx.cs page I was working, used to compile fine and some time gave mysterious error of a variable not defined or function not defined or sometime variable or the function defined two times. I changed possibly each and every variable and function name but there seemed no effect , but after entering a simple space or a new line at any place in the file used to solve the compile error. At one time I tried to save the file (in a different encoding as i am used to experiments) and found that the file was not saving in the correct encoding (i.e. the ansi encoding because the file had a unicode character ), I removed the unicode character and that compile error didn't bothered me again.
This unicode character problem could be (not a hard and fast rule) there so you could check it.
Nuke & restore using source control (TFS instructions here):
Make sure you have everything checked in
Exit Visual Studio
Rename the project directory to .Bak (effectively deleting it)
Reopen Visual Studio and in source control:
Get Specific Version
check 'Overwrite... not checked out' and 'Overwrite ... even if local version matches'
Re-open project
Another problem: Make sure some source files are not newer than the current date (or your date is set back). Often this happens in apps where you are doing logic that requires certain things to happen differently on certain dates. You change your clock to test it, make a revision to the source with the date advanced, set the date back, and viola, rebuild does not rebuild that file.
You say 'typing it in again' - can you try just saving? After 40 years since MULTIX the .net build still decides what has changed by checking the file timestamp.
good luck!
When you get the error, is it always on the VB calling C# side, or vice-versa, or does it work both ways?
If the answer is either of the first two situations, try building the "callee" project within the solution before building the "caller" project to see if it stops the situation.
Also, just in case it may jog something for you to think about, does this error crop up when you change a VB file or a C# file, or is there no correllation?
Oh, and sorry this looks like an answer instead of a comment, I cannot post comments yet (need 50 rep).
I'm new to VB6 but i'm currently in charge of maintaining a horror of editor like tool with plenty of forms, classes, modules and 3rd party tools all chunk together like the skin faces on that guy in the texas chainsaw massacre...
What i don't understand is why i get different results when i run the app in debugging mode, vs when i compiled it and run it on my devevelopment pc vs when i installed it on a different pc.
Yes i know i'm dumb, so please direct me to where i can find out more about this. I'm hoping to find out something like different linking, registry related etc connection that i'm simply not getting right now, i.e. something like wax on, wax off :P
The main pain in the neck is when i'm trying to debug some errors from my QA and i need to find a spare pc to test this on plus i can't directly debug because i don't know where the code is if i do it that manner.
Thanks.
i run the app in debugging mode vs when i compiled it and run it on my
devevelopment pc
When you compile you have the option of compiling to native code or pcode. The debugger runs using pcode only. Under rare circumstances when you compile to native code there will be a change in behavior. This particular is really rare. I used VB6 since it's release and I may get it once or twice a year. My application is a complex CAD/CAM creating shapes and running metal cutting machine and has two dozen DLLs. Not a typical situation. At home with my hobby software I never ran into this problem.
There are another class of errors that result from event sequencing problems. While VB6 isn't truly multi-tasking it has the ability to jump out of the current code block to process a event. If it re-enters the same block for the new event interesting things (to say the least) can result. I think this is the likely source of your problems as you software is an editor which is a highly interactive type of software.
In general the problem is fixed by reordering the effected areas. You find the effected area by inserting MsgBox or write to a text file to log where you are. I recommend logging to a text file as MsgBox tend to alter behavior that are timing or multi-tasking related.
Remember if a event fire while VB6 in the middle of a code block and there a DoEvents floating around then it will leave the code block process the event and return to the original code block. If it re-enters the same code block and you didn't mean for this to happen then you will have problems. And you will have different problems on different computers as the timing will be different for each.
The easiest way to deal with this type of issues is create some flag variables. In multi-tasking parlance they are known as semaphores or mutexes. WHen you enter a critical section of code, you set it true. When you leave the routine you set it to false. If it is already true when you enter that section of code you don't execute it.
when i installed it on a different pc.
These are usually the result of the wrong DLL installed. Most likely you have an older version while the target has a newer version. I would download the free Virtual PC and create a clean Window XP install to double check this.
If your problem is event timing this too can be different on different computers. This is found by logging (not MsgBox) suspect regions.
If you can display a screen shot or the text of your specific errors then I can help better.
The first thing to check would be the versions of all the dlls that your app depends on - including the service pack version of the VB6 dll.
Have you any more specific details about what's behaving differently?