I want to use the skill change tweaker to unlock game stages upon reaching a certain skill level. However, upon reaching the specified skill level, I get the error "You do not have permission to use this command."

I will look into this when I get a chance I believe I know what line is the issue given I had left a comment to check if it would work. (It had seemed to work at the time but I forgot about the fact that I had op perms while testing op commands)

How soon will this issue be fixed? It wouldn’t make sense for me to release my modpck until it is.

This issue will probably be fixed either today or tomorrow, depending on when I get a chance to test my fix. When the next update with this included will be released I have no idea as I have been rather busy with courses and am working on adding/fixing a couple things to reskillable/compatskills

Uploaded the fix to Curse. It will be available when they approve it.