Error when deleting classes "Something went wrong with modifying classes"

I’ve cloned images from other datasets as part of my null set successfully with no issues, but for some reason, my recent null additions added classes that I cannot delete. I go through the whole steps of going to “Classes & Tags”, clicking “Modify Classes” and check “delete” checkbox on every class I delete. Again I’ve done this before with this same project (I am using the free version), but when I try to remove (rename also doesn’t work) the unneeded classes I get the error “something went wrong while modifying classes.” Even after the cloned images were removed from the dataset, and deleted from the project, the classes are still there with count 0 and I still get this error when I try to delete the classes.
TLDR: When I get images from other roboflow datasets but don’t want annotations, I get an error when I try to delete the related classes

same issue. it’s a bug. please fix ASAP

It was a regression, fixed a few hours ago!