Group Can't be deleted

I am not sure if I am doing something wrong. But when I try to change the name of groups or delete nothing happens. When I try to delete and press confirm the group stays.

It may be because I used non-standard letters (Greek) so it became all garbled.

Here is an image of the problem

Shouldn't care about characters. I'll look into this today. In the mean time, I can delete any you don't want.

Thanks Keleth! Please delete all the groups. I'll just start again.