Fallback handler could not load library in Windows 10 64bits

[aenah]

Hello, everyone.

I have finished my game. This asset (SIMPLESQL) works great, but I have an issue: in Windows build (Architecture=x86_64), my game crashes at the beginning. When I look the log (output_log.txt), I can see the error message:

Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/sqlite3
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/sqlite3.dll
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/sqlite3
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/libsqlite3
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/libsqlite3.dll
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/sqlite3
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/sqlite3.dll
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/sqlite3
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/libsqlite3
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/libsqlite3.dll
Fallback handler could not load library: C:Users/whatever/downloads/myGame/mygame_data/Mono/libsqlite3

The funny thing is that if I close the game and re-launch it, everything works perfectly.

First I made the build in mac, and then I copy the result folder (with .exe and others files and folders) in my Windows 10 PRO (64bits).

In Unity Editor and builds for macosx, the game works perfectly.

Can anyone help me?

Thanks a lot!

[echo17]

I don't have Windows 10 to test on, but I'm a little bit confused. How are you able to build a mac executable that can run on windows? I didn't think that was possible.

One thing you might want to check is that you have the correct library selected in the SimpleSQL options. In Unity, go to Tools > SimpleSQL > Options and select the universal library. If it is set to Mac, then it won't copy the sqlite dll that is required for windows.

[aenah]

Aug 26, 2019 12:44:05 GMT echo17 said:

I don't have Windows 10 to test on, but I'm a little bit confused. How are you able to build a mac executable that can run on windows? I didn't think that was possible.

One thing you might want to check is that you have the correct library selected in the SimpleSQL options. In Unity, go to Tools > SimpleSQL > Options and select the universal library. If it is set to Mac, then it won't copy the sqlite dll that is required for windows.

No, no. I'm sorry if I explained it wrong.

I build in Macosx. Then, I copy the build package in Windows.

My configuration is the next one:

[aenah]

More information about this: if, before launch the game, I copy manually the file sqlite.dll in my game`s root folder, everything works ok.

Any idea??

[echo17]

That is very odd indeed. By selecting the universal option, it should automatically copy the sqlite3.dll file into your game's directory. Perhaps Windows 10 has some limitation (security perhaps?) that prevents the dll from being copied.

[aenah]

Aug 27, 2019 12:46:35 GMT echo17 said:

That is very odd indeed. By selecting the universal option, it should automatically copy the sqlite3.dll file into your game's directory. Perhaps Windows 10 has some limitation (security perhaps?) that prevents the dll from being copied.

I dont think so, there are others dlls in the project.


I have done a new test. I upload my game to STEAM (in mode beta) and, after download it in Steam app, I have execute the game. Now, the error messages are like this one:

Fallback handler could not load library: C:/Program Files (x86)/Steam/steamapps/common/mygamename/mygamename_data/Mono/sqlite3

I have explore this in my computer and I don't have Mono folder. Can this be a clue?

[echo17]

Aug 27, 2019 15:07:29 GMT aenah said:

I dont think so, there are others dlls in the project.

Sorry, I should have mentioned that SimpleSQL does something unique in that it copies the sqlite3.dll file into your application's directory at runtime when a scene with SimpleSQLManager in it runs. So that dll does not show up until a scene with SimpleSQLManager in it runs. This goes back to a Unity limitation that did not allow non-managed dlls inside an application at build time, only runtime.

Thinking about that, it may be a timing issue. Are you making any calls to your database in the Awake method of any scripts? SimpleSQL does its initialization (including copying the dll) in its own Awake method, so if your script is being called first, that might be the culprit. If so, there are two alternate solutions to this:

1) Move your database calls outside of any Awake methods. Awake should not reference other components, only internal initializations. You can use Start for accessing other components or systems since all script Starts will call after all script Awakes.
2) Change the script order in Unity so that SimpleSQL starts up first. See this link for more information: link

Aug 27, 2019 15:07:29 GMT aenah said:

I have explore this in my computer and I don't have Mono folder. Can this be a clue?

I don't think that should matter. The sqlite3.dll file shows up in the root application folder. When I build the Demo projects included with SimpleSQL, and run the first demo, the sqlite3.dll file is copied at the start of the scene. Folder structure looks like this on Windows 7:

[aenah]

Thanks for the explanation. I will try change the scripts order, as you said.

Anyway,  I got it to work this morning doing the next steps:

1. I make a Windows build in x86 architecture instead of x86_64.
2. I have copied sqlite3.dll in my game´s root folder.

If I follow these two steps, the game works perfectly.  Does this make any sense to you?

[echo17]

Yes, that does make sense. SimpleSQL should be copying the sqlite3.dll file into your application root folder for you, but you can just as easily put it there yourself. Either way, that is the library and location it is looking for.

Still not sure why it isn't copying the file there when you run the scene, though.