Why would one character out of 3 not be able to right click in the empty spell gem to select a spell. Works fine on my other characters. On this one I right click the empty gem and no menu appears Is it a setting?
Are you clicking the spell or using a hotkey? If its a click, verify that you don't have any transparent boxes over the spell gem. Happens to me pretty frequently in windows mode, slight resizing throwing everything off.
It does this to my characters sometimes too. I log out and back in, or reloading the current UI works too.