WowAce

I got this message in Classic Wotlk. 10:00:17] Decursive: There are too many Lua errors in your User Interface (48 errors). Your game experience may be degraded. Disable or update the failing add-ons to turn off this message.
You may want to turn on Lua error reporting (/console scriptErrors 1).
[10:00:17] Decursive: Decursive is merely reporting the issue. So, don't shoot the messenger and address the actual problem.
[10:00:17] Decursive: Here is the last non-Decursive UI error: bad argument #2 to '?' (Usage: local success = C_CVar.SetCVar(name [, value, scriptCVar]))

The message is quite clear, this is not Decursive's fault. Type console scriptErrors 1 in your chat to see all the errors and report them to the add-ons authors.