无法加载DLL'SQLite.Interop.dll'：找不到指定的模块。 Windows Server 2012上的错误

Question

I have a multi-project solution (C#) that I am trying to deploy to one of our test servers. All the projects are being built for x64, with the 'Prefer 32 bit' disabled where applicable.

Some of the projects reference a SQLite dll set that uses the SQLite Encryption Extension (not managed by nuget). When I build and install the solution on my local dev machine, the application and windows service are able to function properly, no problems.

When I try to install the same package on one of our test servers, running 64-bit Windows Server 2012, I get the "Unable to load DLL 'SQLite.Interop.dll': The specified module could not be found." whenever I try to communicate with the SQLite database. I have triple checked that all the appropriate DLLs are in the program folder after installation.

In my VS solution, I have tried creating the x86/x64 folders, setting Copy to Always, but to no avail. I have also copied the DLLs from my local install folder into the server folder just to see if something got messed up along the way.

Could it be a permissions issue? I'm an elevated user but not a full admin on the server, whereas I'm a full admin on my machine. I've tried manually modifying the permissions on the program folder to see if that was an issue, but had no luck with that either.

So to summarize, the project is being explicitly built for x64, it has the right DLLs in the right folders, and it works on a local install. I'm at a loss as to why it won't work on the server install. I've looked through countless threads on StackOverflow, MSDN, and SQLite's website, all usually suggesting the x86/x64 folders, but that hasn't been working for me. I'm hoping someone can help me out here.

Thanks!

Answer 1

Was actually able to figure it out after a bit more debugging. The Visual C++ runtime that was installed on the server wasn't the right version. I added the Merge Module to the installer for the version my project was expecting, reinstalled the app on the server, and now it's working beautifully.

For those who have this issue, look for the right version of the VC++ runtime in C:\\Program Files(x86)\\Common Files\\Merge Modules . If you don't know what version you need, use something like dependency walker on the machine that is throwing the error. Mine told me I was missing VC140 , so that's the module I copied into my project and added to the installer.