MacOS FontBook shows error when validating font files

[snakebyte69]

1 serious error was found. Do not use this font file.

I'm sure it's some annoying Apple requirement that's an easy fix.

[oktophonie]

It would be helpful of Font Book to give some information about what the specific error is :)
Unfortunately we haven't been able to reproduce this problem locally, yet.

[snakebyte69]

I've tested again with the new version v0.52.
I works fine now, cheers!