TYPO3 Core

Steps to reproduce:

1. Include any form definition
2. Rename the file
3. The Form Content Element in the Backend shows 'The file "..." does not exist.' That's fine.
4. The frontend however shows the exception "The options "invalid" were not allowed (allowed were: "rendererClassName, renderingOptions, finishers, formEditor, label")"

This Exception is not helpful at all.

We could throw an Exception with a meaningful message instead before the validation of the allowed array keys.

This is just a suggestion. If this was done on purpose (for example to not disclose the path to the file on the server) its fine as it is.