Thank you for your response! :)
The plugins that are throwing errors aren't actually being used. I've kept them enabled just to avoid accidentally breaking something, but I'll try disabling them now and see if that makes any difference.
If I leave Build Bitmap Font enabled, the game takes a 20~ extra seconds to start. I believe the issue has also happened with this option enabled, although I'm not completely sure.
I wish it were easier to test this problem, but the bug is very rare—I'd estimate it happens about 1 out of every 100 launches. It also occurs across multiple devices, so I'm fairly confident it's not specific to my hardware.
FOSSIL is a very important plugin for my project, so I'd like to suggest a possible improvement. If the Bitmap Font plugin encounters an error or fails to load the font correctly (it seems like it can detect this from the console), the game could display an error message such as:
«An error has occurred and a font failed to load correctly. Please restart the game.»
This would be much better than allowing the game to continue without the font loaded, since players can otherwise keep playing with missing fonts.
If you wish to implement this, let me know ^^
In the meantime, I will make tests without the FOSSIL plugin so I can know for sure that's the cause.