I have been assigned a problem where Borland C++Builder 6 is used.
Building a DLL project in my development environment on my laptop works fine, and using the DLL on the target machine works fine.
The problem arises when the DLL is built on a build machine that also creates the install package. That machine uses the exported makefile from C++Builder's .bpr file to build the DLL. Running the same program as previously with this DLL does not work OK (a call to a constructor seems to be hanging since debug printouts after the call are never seen).
I have built the DLL using the exported makefile on my own machine too, just to test, and that DLL does not work, either.
So, in short, the DLL works fine when built in Borland C++Builder 6, but NOT when built using the exported makefile. No code changes made.
Does anybody have any ideas what the problem might be? This is a very vague question, but the problem is very strange too.
I'm getting a DLLNotFoundException in standalone builds on some windows machines, others work perfectly. Dll file is definitely in the plugins folder, copied it to the projectName_Data folder too but no difference.
Also attempted to add dll to streaming assets folder and set new path (Environment.SetEnvironmentVariable) as above but that didn't work either.
Using Unity 4.5.5 btw
Any help at all would be greatly appreciated!!!
What I found is that the error DllNotFoundException is, in some circumstances, very misleading. Unity is not to blame for this because when something goes wrong with dll loading, Unity simply doesn't have that dll in memory and tells you so.
As Keysosaurus says, Visual C++ Redistributable must be installed for your standalone version to work and in most cases this solves the trouble but there can be other reasons like third party dependencies.
In case you are using third party libraries then you must also copy all the needed DLLs or SOs to your executable's folder.
For example I am working with OpenNI 2 and when I build I immediately copy all files from C:\Program Files (x86)\OpenNI2\Redist folder to the folder that contains the .exe. Not doing this results in DllNotFoundException.
Also don't forget that DLLs (and SOs) must match the architecture you are targeting so if you are targeting x64 (64 bit) then your DLL must be x64 too and if you try to use a x86 (32 bit) DLL Unity will be confused and will not load that giving you the same error.
As a side note bear in mind that Unity 5 comes both in 32 and 64 bit versions. In order to run your game in Unity Editor, all third party libraries must be present in both x86 and x64 (in Unity's conventional folders) or at least the one that matches you Unity Editor's architecture.
I discovered that the problem was that players needed Visual C++ redistributable installed, which can be downloaded here:
https://www.microsoft.com/en-gb/download/details.aspx?id=40784
This is driving me crazy. I have developed a .NET COM DLL that is used by a VB6 DLL wrapper in order to update and replace some legacy functions in an application.
I am now trying to remove the requirement to use regasm on client machines so have worked out how to do that on a test DLL which all works fine.
I branched the DLL just in case and added an app.manifest file. Everything else worked out fine and I got it all working. The manifest is embedded and Visual Studio 2012 generates a mydll.dll.manifest file in the release folder.
Then I went back to the original trunk and added an app.manifest file (no point in merging as there were no code changes). I copied the contents of the branch into the app.manifest file and built the release version. The manifest is embedded in the DLL but no mydll.dll.manifest file is generated.
I know that it's not strictly necessary to have the mydll.dll.manifest file but I'd like things to be consistent (and for some reason the test process doesn't produce the same results with the trunk version) so how can I force it to be created?
This is a VB.NET DLL project so it doesn't have (or I can't find) the 'Generate Manifest' property drop down mentioned in the first answer here. How can I set this? Or is there a way to set it by editing the project file directly?
References:
Original walkthrough article and some corrections.
Overview by Junfeng Zhang in two articles plus a useful tool
You are making a fairly common mistake. A reg-free COM manifest helps an application find a COM server without looking in the registry to locate the DLL. Embedding the manifest in the DLL is like trying to solve the chicken and egg problem, Windows cannot possibly find that manifest if it cannot locate the DLL first.
The manifest needs to be part of the client app. Which is tricky since it is VB6, it doesn't support embedding manifests in its executables.
You could tinker with the mt.exe tool, an SDK utility that supports embedding manifests in an executable. You'd have to run it by hand after building the VB6 binaries. That's unfun and very likely to cause trouble when you forget. It is in general not a joyful tool to use, documentation is meager, incomplete and unhelpful, a chronic problem with manifests.
The fall back is a separate app.exe.manifest file, what Windows will look for next when it cannot find a manifest embedded in the executable. Where "app.exe" must be renamed to the name of the VB6 program. The EXE, not the DLL. This now also gives you a chance to avoid having to register the VB6 DLL, presumably what you really want if you truly want to make your program run reg-free. The disadvantage is that it will not work when you debug your VB6 program, wrong EXE. You'd also need a vb6.exe.manifest, located in the VB6 install directory.
Needless to say perhaps, very hard to get ahead with VB6 here. It just wasn't made to help you do this, they didn't have a time machine in 1998.
I have to admit that I don't know VB at all, but in the case of C++ and C# Visual Studio projects I previously had to resort to calling mt.exe in a post-build step in order to get the DLL manifest I wanted. Maybe that workaround would work in your case as well?
I'm getting an 'AccessViolationException' 'Attempted to read or write protected memory' when calling a method in an x86 dll when running on an x64 platform (Windows 7). Everything works great on x86 platforms.
I've read many, many posts about similar problems but haven't been able to get my code to work.
I'm in the process of trying to make our old x86 app work happily on Windows 7 (x64) and Server 2008 R2 (x64). The app is an assortment of VB6 , VB.Net, C#, MicroFocus COBOL and C++. (We couldn't think of any other languages to throw in at the time). The DotNet code was originally written in Visual Studio 2003 for DotNet 1.1. I've ported the code up to Visual Studio 2010 and DotNet 4.0. I've set the target for all the projects to x86. When I call into un-managed 32 bit dll's I get the above error.
Our InstallShield setup routine is installing the x86 dll's into C:\Windows\sysWOW64 instead of C:\Windows\System32. This behavior seems correct. The dll's are some COBOL object code and runtime components linked together into a 'C Style' dll. I don't think the problem has to do with COBOL or the linking process as I also ported up a sample app from Code Project with a VB.Net WinForms app that calls a simple C++ dll, all targeted to x86. I get the same error there. I've also tried building a C++ command line app to call the dll. The Load Library succeeds. GetProcAddress succeeds. Calling the function pointer for the particular method fails. Our VB6 apps can call the dll's just fine when running on Windows 7 x64. I've also tried turning off UAC and setting the requestedExecutionLevel in the manifest to the highestAvailable. I've tried running as administrator.
Seems like this should work, but not sure what to try next. Any ideas?
On x64 .net programs will be run as 64-bit programs and cannot call 32bit-dlls.
Try compiling the application with target x86 instead of "Any Target". You can also force the
target of the built .exe with the .Net CorFlags.exe utility to run in 32bit-mode.
Of course your program will then run in the 32bit environment, especially it will only have a maximum of 2gb of RAM.
Good news,
We investigated DEP as a possible cause of the problem as we saw that even our VB6 code will fail when DEP is turned on. We noticed that the VB.Net code was failing in the same way as VB6 when DEP was on. Apparently our COBOL dll's do something that DEP isn't happy with. Unfortunately the DotNet assemblies don't seem to respect the operating system DEP setting, so you have to turn off DEP with using editbin.exe:
editbin.exe /nxnocompat:no
I still have to test it on our full application, but it looks like we have a solution!
I have a seemingly random problem where my project will run using an old version of a DLL file that no longer exists. Sometimes the real version of the DLL file will be used, other times an ancient version of the DLL file will be used. Who knows where Visual Studio is getting this DLL file from - it's months out of date!
I know that it is using the old DLL file, because when the application runs I start getting weird 'TypeLoadExceptions', complaining that methods don't exist or don't have implementations.
The following actions will sometimes help, sometimes not:
Restarting Visual Studio
Restarting the computer
Cleaning and rebuilding the solution
Deleting everything in \WINDOWS\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files
Searching for and deleting instances of the DLL file in \Documents and Settings\username\Local Settings\Temp
Sometimes I perform all of the above steps, and it still uses an old copy of the DLL file. Where is it hiding it?!
The same issue exists on our TeamCity server which is using MSBuild. When TeamCity tries to run unit tests it uses an old DLL file.
Now, I know that I can use assembly redirection in the web.config file, but the version number of the DLL file hasn't changed (I don't bother to update it, so it just stays at version 1). I don't want to have to start versioning the DLL files just to solve this problem. I would just like to know which particular caches I need to clear so that I can get on with developing.
It hides it in the GAC. There it may reside indefinitely. Using a more recent version may indeed solve the problem, but there is an outstanding bug in Visual Studio that has to do with choosing the correct version of DLL files. (If DLL Hell wasn't bad enough, the Visual Studio team is making it worse!)
Finding it in the GAC is tricky, and I cannot advise you on how to do that, but once the old version is deleted from there, it will not be found again. Sometimes, even though you are pointing the compiler at a newer version (by date), it will use the older version, because it has the same version level (by version). That is its bug.
Who knows where Visual Studio is getting this dll from - it's months
out of date!
The Modules Window is your friend...
It'll tell you exactly where that file is coming from. You can even use it with arbitrary processes if you attach the debugger.
I too would guess that they're hiding in the GAC.
You can look in 'C:\Windows\assembly' to see all the dlls and unregister yours from there.
The problem may exists with the build order or your projects.
If your Test project is built before the application project, this cause the behaviour you describe. To fix this: right click on your main project in VS and select the Project Dependencies... option and check the build order. Changes to the build subsequence can be made here by correctly setting these dependencies.
I had a similiar problem (but without Visual Studio). I am loading a .NET dll using UnsafeLoadFrom.
On one computer (a terminal server) the old file still remains being used, regardless of updated version numbers, etc.
The reason is simple: As long as a program instance is running, which has already loaded the old dll, the new dll will never be used. All further UnsafeLoadFrom will become the old dll although the old version doesn't exist on the harddisk anymore, because it has already loaded some time ago.
The solution is to shut down all running instances of the application or even restart the computer. Then all new instances will get the updated dll.
In my case, this was caused switching to Release mode, which had a different configuration (that used different location of the DLL).
In my case, I use Visual Studio to Publish Website, and though I check the reference of the dll file has changed, but the published dll still is old. Finally I new a Publish Web Profile and choose the right configuration (such as Debug - x86 / Release - Any CPU), publish again then the dll is corrected.
While this question is old, maybe someone will stumble upon it again in his/her quest for finding a solution.
In my case i got a CS0433 error for an ASP.Net page. After deleting the content in the obj\ and bin\ folders of the project, it worked again. Probably has to be done with a closed Visual Studio. Maybe also clean out those folders in referenced projects in the same solution (if used in the project and not pulled via Nuget).
In my case, the old DLL was in
C:\Windows\Microsoft.NET\assembly\GAC_MSIL\MyDLL\MyDLL.dll
It DID NOT show up in c:\Windows\assembly.
I did a search of my drive for MyDLL, and it showed up as indicated above. I was debugging my test app at the time, and tried to delete the offending folder...no go...it was locked by Visual Studio. I had to stop debugging my app, close Visual Studio, and then delete the folder. Problem solved!! I don't know how my DLL got there, but it hasn't showed up there since I deleted it.
It's possible that the DLL is being referenced from another folder. It could even be on a network drive if you have one in your PATH environment variable. Here's how Windows searches for DLLs:
http://msdn.microsoft.com/en-us/library/7d83bc18%28v=vs.80%29.aspx
In My Visual Studio 2015, I ensured that the offending Visual Studio project's Reference Path Listing is empty:
If you find such problem ,delete your Reference dll and pdb extensionfile add new references and rebuild your project .This often happens due to no rebuild of project,commit and updates.
The fix for me was making sure that the virtual directory in IIS was pointing to the correct directory. I have two projects on my system, a v4 and a v5. The virtual directory on my dev system was pointing to the v4 bin directory instead of my v5 bin directory - oops!
The file that was being cached in the dll, I couldn't trace the file, so I ended up renaming the file. This might not resolve the problem mentioned here but this was the fix that worked for me related to this question.
I tried a ton of things including re-installing VS 2107.
You can see where the DLL files are being loaded from in your Output window. After going through all mine looking for project DLL, I found it.
Clearing this worked for me.
C:\Users\YourUser\AppData\Local\assembly\dl3\222Q4G1T.8AT\JBEAR7PB.E3J\8bfcf9ab\6e61cbd5_30acd401\YourDLL.dll'
I actually deleted all the files in:
C:\Users\YourUser\AppData\Local\assembly\
Holy Crow! I had an old, old suite of applications including 2 web services and a bunch of class libraries and a click once application. Well, click once stopped publishing for VS 2005 with a bunch of 'not found' errors. So, rather than hack away at my registry as suggested on this site, I figured it was time to upgrade the projects to 2017. Well, when I did this, the projects references in my web service projects got lost. Then, rather than helpfully just telling me that with errors, VS 2017 must have went to some cached file in C:\Users\XXX\AppData\Local\Temp\WebSitePublish or C:\Users\XXX\AppData\Local\Microsoft\VisualStudio\8.0\ProjectAssemblies or C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root and 'helpfully' just used those files instead! I had to do a hardcore search with a custom program to find all the files on my C:\ drive and delete them before I finally got the errors!