Error: Couldn't load project data at path ".". Is the .pck file missing?
If you've renamed the executable, the associated .pck file should also be renamed to match the executable's name (without the extension).
On bootup on windows
I've been trying to replicate this error but I wasn't able to :/ I developed the game with Godot which allows .pck embedding, so I'm not sure how it could be "missing", I'll try to look into it as it's probably a problem with some export setting.