Clear up validation error message

[geekygirlsarah]

What GitHub issue does this PR apply to?

Resolves #745

What changed and why?

Clears up an error message on validating the meta file. Also cleans up the formatting around the error message strings

Checklist

• I claimed any associated issue(s) and they are not someone else's
• I have looked at documentation to ensure I made any revisions correctly
• I tested my changes locally to ensure they work
• For language files, I have validated the edited files are valid JSON and data shows up correctly
• For website code edits, I have added or edited any appropriate unit tests for my changes

Any additional comments or things to be aware of while reviewing?