Using Spellbinder R5 (the latest version) I get the following error if I try to use it while playing a Paladin, Warrior, Druid and Priest. Does NOT crash when the class is Death Knight, Mage and Hunter. Can't speak for the Rogue, Shaman and Warlock classes. Tested with a fresh install of WoW 3.1.1 with no other addons running.

Error occured in: Global
Count: 1
Message: ...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua line 1656:
AceConfigRegistry-3.0:ValidateOptionsTable(): SpellBinder.args.school4.name: expected a string or funcref, got 'nil'
Debug:
[C]: ?
[C]: error()
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:42
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:37
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:173
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:168
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:207
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:182
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:217
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:182
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:248 ValidateOptionsTable()
...-3.0\AceConfigRegistry-3.0\AceConfigRegistry-3.0.lua:294 app()
...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1656 Open()
SpellBinder\SpellBinder.lua:30 value()
..\FrameXML\ChatFrame.lua:3231 ChatEdit_ParseText()
..\FrameXML\ChatFrame.lua:2930 ChatEdit_SendText()
..\FrameXML\ChatFrame.lua:2951 ChatEdit_OnEnterPressed()
[string "*:OnEnterPressed"]:1:
[string "*:OnEnterPressed"]:1