Okay, will have a other looks. Seems the function ENCHANTING:SetRuneSlotItem is missing now.
Hm I don't know the addon and there seem to be some problems with the menu shown above other menus (like create, extract- >if you got Quick Enchanter active and change to the other menus).
Exchanged the function and removed something below that to suppress the sound, but now the sound is always played. The hack he used there is not working again anymore.
The addon in total would need a rework!
I recommand switching to another addon like CarftStore FixedAndImproved for enchanting stuff.
Redownload and test it please
I'm providing a version here with the libraries removed and addon code changed to support the non-libstub global versions soon.
QuickEnchanter (hopfully fixed) 0.45.1
You need the following libraries installed:
LibAddonMenu-2.0
LibCustomMenu
LibEnchantingStation