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
I've read about running 32 bit DLLs in 64 bit environments, especially here. But I'm still getting errors. Here's what I have. I have a real old 32-bit DLL that can't be converted to 64 bit. I have another DLL, my own, written in VB.NET, that I've compiled as x86. It calls the older one. My DLL is part of a Windows Service which I've compiled to x86 as well. So all x86 running on a 64-bit Win2012 server. The older DLL is actually installed on the machine itself, not part of my DLL or the Win Svc because of the nature of that DLL.
The older DLL is invoked using the standard X = CreateObject("oldDLL"). Everything works until I try to call a method on X. Then the method can't be found.
Any thoughts?
I created an installer for my AnyCPU DLLs. I've marked my assemblies with teh Assembly=.net directive in my project as well. The installer seems to be able to register the COM servers successfully on my XP 32bit machine, but fails to do so in my Windows7 Machine. I did run the installer in admin mode. Also I looked up the Win764 registry and found those CLSIDs in the reigstry. So looks like the MSI did put some entries in the registry but somehow they are not being recognized as valid COM Server entries (OLE Viewer also didnt enumerate my server).
Any idea why this would happen? Any extra config do I need to add to my project?
thanks
Apparently you need to compile your msi as a 64-bit native binary to have the dlls registered in 64 bit mode.
I would like to know when do we need to place a file under
C:\Windows\System32 or C:\Windows\SysWOW64, on a 64-bits windows system.
I had two DLL's, one for 32-bit, one for 64-bit.
Logically, I thought I'd place the 32-bit DLL under C:\Windows\System32, and the 64-bit DLL under C:\Windows\SysWOW64.
To my surprise, it's the other way around! The 32-bit one goes into C:\Windows\SysWOW64, and the 64-bit DLL goes into C:\Windows\System32.
Very confusing stuff. What's the reason behind this?
I believe the intent was to rename System32, but so many applications hard-coded for that path, that it wasn't feasible to remove it.
SysWoW64 wasn't intended for the dlls of 64-bit systems, it's actually something like "Windows on Windows64", meaning the bits you need to run 32bit apps on a 64bit windows.
This article explains a bit:
Windows x64 has a directory System32 that contains 64-bit DLLs (sic!).
Thus native processes with a bitness of 64 find “their” DLLs where
they expect them: in the System32 folder. A second directory,
SysWOW64, contains the 32-bit DLLs. The file system redirector does
the magic of hiding the real System32 directory for 32-bit processes
and showing SysWOW64 under the name of System32.
If you're talking about an installer, you really should not hard-code the path to the system folder. Instead, let Windows take care of it for you based on whether or not your installer is running on the emulation layer.
I should add: You should not be putting your dll's into \system32\ anyway! Modify your code, modify your installer... find a home for your bits that is NOT anywhere under c:\windows\
For example, your installer puts your dlls into:
\program files\<your app dir>\
or
\program files\common files\<your app name>\
(Note: The way you actually do this is to use the environment var: %ProgramFiles% or
%ProgramFiles(x86)% to find where Program Files is.... you do not assume it is c:\program files\ ....)
and then sets a registry tag :
HKLM\software\<your app name>
-- dllLocation
The code that uses your dlls reads the registry, then dynamically links to the dlls in that location.
The above is the smart way to go.
You do not ever install your dlls, or third party dlls into \system32\ or \syswow64. If you have to statically load, you put your dlls in your exe dir (where they will be found). If you cannot predict the exe dir (e.g. some other exe is going to call your dll), you may have to put your dll dir into the search path (avoid this if at all poss!)
system32 and syswow64 are for Windows provided files... not for anyone elses files. The only reason folks got into the bad habit of putting stuff there is because it is always in the search path, and many apps/modules use static linking. (So, if you really get down to it, the real sin is static linking -- this is a sin in native code and managed code -- always always always dynamically link!)
Ran into the same issue and researched this for a few minutes.
I was taught to use Windows 3.1 and DOS, remember those days? Shortly after I worked with Macintosh computers strictly for some time, then began to sway back to Windows after buying a x64-bit machine.
There are actual reasons behind these changes (some would say historical significance), that are necessary for programmers to continue their work.
Most of the changes are mentioned above:
Program Files vs Program Files (x86)
In the beginning the 16/86bit files were written on, '86' Intel processors.
System32 really means System64 (on 64-bit Windows)
When developers first started working with Windows7, there were several compatibility issues where other applications where stored.
SysWOW64 really means SysWOW32
Essentially, in plain english, it means 'Windows on Windows within a 64-bit machine'. Each folder is indicating where the DLLs are located for applications it they wish to use them.
Here are two links with all the basic info you need:
MSDN File System Redirector
SysWow64 Explained
Hope this clears things up!
System32 is where Windows historically placed all 32bit DLLs, and System was for the 16bit DLLs. When microsoft created the 64 bit OS, everyone I know of expected the files to reside under System64, but Microsoft decided it made more sense to put 64bit files under System32. The only reasoning I have been able to find, is that they wanted everything that was 32bit to work in a 64bit Windows w/o having to change anything in the programs -- just recompile, and it's done. The way they solved this, so that 32bit applications could still run, was to create a 32bit windows subsystem called Windows32 On Windows64. As such, the acronym SysWOW64 was created for the System directory of the 32bit subsystem. The Sys is short for System, and WOW64 is short for Windows32OnWindows64.
Since windows 16 is already segregated from Windows 32, there was no need for a Windows 16 On Windows 64 equivalence. Within the 32bit subsystem, when a program goes to use files from the system32 directory, they actually get the files from the SysWOW64 directory. But the process is flawed.
It's a horrible design. And in my experience, I had to do a lot more changes for writing 64bit applications, that simply changing the System32 directory to read System64 would have been a very small change, and one that pre-compiler directives are intended to handle.
Other folks have already done a good job of explaining this ridiculus conundrum ... and I think Chris Hoffman did an even better job here: https://www.howtogeek.com/326509/whats-the-difference-between-the-system32-and-syswow64-folders-in-windows/
My two thoughts:
We all make stupid short-sighted mistakes in life. When Microsoft named their (at the time) Win32 DLL directory "System32", it made sense at the time ... they just didn't take into consideration what would happen if/when a 64-bit (or 128-bit) version of their OS got developed later - and the massive backward compatibility issue such a directory name would cause. Hindsight is always 20-20, so I can't really blame them (too much) for such a mistake. ...HOWEVER... When Microsoft did later develop their 64-bit operating system, even with the benefit of hindsight, why oh why would they make not only the exact same short-sighted mistake AGAIN but make it even worse by PURPOSEFULLY giving it such a misleading name?!? Shame on them!!! Why not AT LEAST actually name the directory "SysWin32OnWin64" to avoid confusion?!? And what happens when they eventually produce a 128-bit OS ... then where are they going to put their 32-bit, 64-bit, and 128-bit DLLs?!?
All of this logic still seems completely flawed to me. On 32-bit versions of Windows, System32 contains 32-bit DLLs; on 64-bit versions of Windows, System32 contains 64-bit DLLs ... so that developers wouldn't have to make code changes, correct? The problem with this logic is that those developers are either now making 64-bit apps needing 64-bit DLLs or they're making 32-bit apps needing 32-bit DLLs ... either way, aren't they still screwed? I mean, if they're still making a 32-bit app, for it to now run on a 64-bit Windows, they'll now need to make a code change to find/reference the same ol' 32-bit DLL they used before (now located in SysWOW64). Or, if they're working on a 64-bit app, they're going to need to re-write their old app for the new OS anyway ... so a recompile/rebuild was going to be needed anyway!!!
Microsoft just hurts me sometimes.
I heard on Windows x64 architecture, in order to support to run both x86 and x64 application, there is two separate/different sets of Windows registry -- one for x86 application to access and the other for x64 application to access? For example, if a COM registers CLSID in the x86 set of registry, then x64 application will never be able to access the COM component by CLSID, because x86/x64 have different sets of registry?
So, my question is whether my understanding of the above sample is correct? I also want to get some more documents to learn this topic, about the two different sets of registry on x64 architecture. (I did some search, but not found any valuable information.)
I ran into this issue not long ago. The short answer is that if you run a 32 bit application on a 64 bit machine then it's registry keys are located under a Wow6432Node.
For example, let's say you have an application that stores its registry information under:
HKEY_LOCAL_MACHINE\SOFTWARE\CompanyX
If you compile your application as a 64 bit binary and run it on a 64 bit machine then the registry keys are in the location above. However, if you compile your application as a 32 bit binary and run it on a 64 bit machine then your registry information is now located here:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\CompanyX
This means that if you run both the 32 bit and 64 bit versions of your application on the same machine then they will each be looking at a different set of registry keys.
Your understanding is correct. There wouldn't be any need for a x64 app to access the x86 CLSIDs since it could never load those components anyway and vice versa.
If you want to create component for use by both x86 and x64 then you need to either create a pair of dlls one built for x86 and the other for x64 and register both in their appropriate parts of the registry. The regsrv32.exe in the System32 folder will perversely register the x64 component and the regsrv32.exe in the SysWOW64 folder will register the x86 component.
Alternatively build a .NET assembly for Any CPU which can used by either CPU architecture.
They aren't separate registries--one is a subnode of the other, and the OS does virtualization to make sure that 32bit apps get their keys and 64bit apps get their keys.
Here is the Wikipedia article on the WOW64 registry which may give you some of the information you are looking for:
http://en.wikipedia.org/wiki/WOW64
I run an x64 bit machine as my desktop; and I have never run into any issues with the different registry configurations.
Per MSDN, there is apparently a difference:
http://msdn.microsoft.com/en-us/library/ms724072(VS.85).aspx
HTH
How to register .NET assembly to be used as COM in pure 64-bit application?
Problem:
By default, if you enable "Register for COM Interop" in build settings, it DOES NOT register type library for 64-bit.
Solution:
To register your assembly which is not in GAC on a 64-bit machine, open cmd window and do:
cd c:\windows\microsoft.net\framework64\v2.x.xxxxx
regasm /codebase "path to your compiled assembly dll"
This will eliminate "Class Not Registered Error" when using native C++ to instanciate .NET assembly as COM object.