Some engines, like Quakespasm, produce an unimportant error message in the console when starting Arcane Dimensions:

"Unknown Command: Max"

This is due to a semicolon on line 190 in the quake.rc for this mod. The semicolon escapes the comment for most engines, which means that text after it will be treated as an attempted command.

If one just changes it to a comma, there's no more error output.