Unable to start recording "Error Opening 'C:/Users/XXXX/Videos/2022-08-01 01-40-07.flv': Function not implementedCouldn't initialize muxer"

[KesForShort]

I'm trying to start a recording for the first time. I've had OBS installed for a long time and I've used the virtual camera before but never recorded before and now I'm getting this error >.<

I've attached my log

all my searching has just led to "reinstall OBS forehead" and I tried that but had no success X.X