OK, I'm new to Mac/OSX so to me a reinstall sounds pretty drastic. Will read up about it.
Haven't tried on a different user account yet. And not sure if file sharing is on or off. Will also look into that.
Thanks for the help!
I have the same issue: I can create and delete folders and I can copy files and folders, but I cannot move them. Tried drag and drop but won't budge, like OP. Very annoying.
Don't feel like reinstalling to see if that would solve the problem.
I come from Linux, so comfortable with the command...