Valid mcmeta file crashes the game

I found a random bug generator. That was infuriating...

Game Crashes while loading a valid mcmeta-file.

See attachments:

1. mcmeta-file (Working)
2. mcmeta-file (Not-working)
3. crash-report

Look at the mcmeta-files at letter-position 874(CRLF included, generally invisibles included). Only one Number, the number 51 is different between these files and it makes a difference between minecraft crashing and minecraft working.