Bob's UI extension card started throwing a vague 'missing nl.middlePane.errorCategories.undefined translation' error when trying to execute a serverless function, which previously worked fine.

The investigation revealed that the 'missing translation' error was masking a 'function not found' error. This was caused by the `app.functions` folder being omitted from the project build/upload after switching from GitHub deployment to manual uploads. Restoring the correct project folder structure resolved the issue.