Improve error handling generating multiple files

[MarkVanDijkHG]

Describe your changes

Give a useful error when the array was not present.

Type of change

Please check only ONE option.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How was this tested?

Tested by having a correct and incorrect path.

Checklist before requesting a review

• I have reviewed and tested my changes
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I selected develop as the base branch and not main, or the pull request is a hotfix that needs to be done directly on main
• I double checked all my changes and they contain no temporary test code, no code that is commented out and no changes that are not part of this branch
• I added new unit tests for my changes if applicable

Related pull requests

N/A

Link to Asana ticket

https://app.asana.com/0/1205090868730163/1205885370050586