Projects won't launch

[ihatethefrench]

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Describe the bug
Projects don't seem to launch at all, always outputting the error below

Relevant section from script.py:

To Reproduce
Steps to reproduce the behavior:

1. Build project using run_wizard.py --clean --skins <path_to_skin> (this is scripted)
2. Attempt to run project using renpy 7.5.0 by invoking renpy.sh fansim-engine/projects/work

Information (please complete the following information):

• OS: Linux
• Python Version: 3.9
• Package name, if applicable
• Launch method: renpy 7.5.0
• Launch target: project