Build looking for DLL in odd places

Unity Engine
,
1

I have a DLL that Unity can find in the editor just fine that connects to some custom periphreals. When I do a build it places My_API64.dll in the plugins directory.

When I go to run the build it has these errors in the log:
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
OpenVR Shutdown

(Filename: Line: 1461)

Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/My_API_64
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll
Fallback handler could not load library D:/Work/Demo 2019/Build/Demo (HTC Vive)_Data/Mono/libMy_API_64.dll

When I copy over the DLL into those 3 spots, the demo works but has a crash that I can’t duplicate in the editor. So first things first, I’m trying to figure out why it would be looking for DLLs in those three random-seeming spots, rather than just the plugins folder.

The only place the DLL is referenced is in a series of 30-40 DLLImport calls to manage calls to its various functions. The DLL is referenced the same way, with no path, in all of my DLLImport calls.

An example:

[DllImport(“My_API_64.dll”, CallingConvention = CallingConvention.Cdecl, EntryPoint = “my_initAPI”)]
public static extern void initMyApi();

2

Hello MrMonkeylicious,

not sure if it is relaled, but I have a c++ dll compiled with vs2017 that is called via dllimport calls, and for some reason it works in unity editor/windows , but not within a window build. I have no idea why. By the way it seems that it is not working either ineditor with unity version 2019.1.

the same c++ dll that works in the editor seems to crash on a cpp “dynamic_cast” in the standalone build. I have the RTTI enabled. If someone has an idea… Thank you in advance.

1 Like
3

Can you post sample code of where it crashes? How does it crash? Is it an access violation?