Quick answer: Godot 4 exported PCK failing to load resources with 'UID not found' error? UIDs not updated after a path rename - rebuild the UID cache before export.
Editor PIE works. Exported build: UID uid://abc... unresolved on a renamed resource.
Rebuild UID cache
Editor > Project > Tools > Rebuild UID Cache. Updates the index that the exporter reads.
Commit .uid files
The cache is regenerated from .uid files. Without them in source control, every fresh checkout regenerates new UIDs.
Verify with godotpcktool
godotpcktool list game.pck | grep .uidUIDs should be present in the PCK. Missing = cache regeneration needed.
“UIDs in Godot are an opt-in indirection. The opt-in needs cache discipline.”
Add 'rebuild UID cache' to the CI build script. Manual steps drift; CI doesn't.