Thank you so much for testing!
Do you have a clue what i could do now?
The only idea i have is downgrading again and reworking to the point im at right now but this can't be the best solution i guess
Not at all sure why you are experiencing difficulty converting the .wav.
I can think of 2 quick options:
1) Download something like Audacity (which is free) and convert the .wav yourself.
2) Wait until tomorrow and I'll upload the converted file for you.
Option 1 would be better for you in the long term as you will have control, but until your peoblem can be remedied, the choice is up to you.