Skada not working

I have had skada for a while now and cant get it to work anymore and keep getting this popping up in my chat window, interfaceskadacorecore.lua.1387: attempt to index field 'validclass' (a nil value)

I've tried reinstalling.. downloading a combat log fix addon.. and even some macros that some people have posted.

Have you tried downloading it from another source?

delete skada settings.

Open WoW folder -> WTF -> account -> accountname -> SavedVariables

once there delete:
Skada.lua
Skada.lua.bak