NotesLoaders fail to load NoteData if Difficulty is spelled wrong

[poco0317]

hilarious issue, great job step artists

Found a case where someone spelled the difficulty "Chllenge" or something similar and, while the game recognizes this as a legitimate chart, it cannot interpret the difficulty. The result is that we have a loaded file complete with MSD, but when we try to view the chart we get nothing because the notedata can't be retrieved through the normal method. The assigned difficulty ingame is also likely incorrect and is based off of the meter given to the chart in the text instead of the difficulty string.

file in question is something "sojoto" in some vocaloid pack