Could copy/pasta text but i have this. it also occurs so often that blizz warning pops up to disable addon.

Love your addon and have used for many years! thanks!

Please, read the message in orange that is clipped in your screenshot. Decursive is merely telling you that another add-on is causing many errors and that you should take care of this problem but it's not Decursive.

The add-on that is causing the issue is trying to use a deprecated API called GetActivityInfo (Decursive does not use this API). You can try to find which add-on is causing this by enabling LUA error reporting in your WoW interface option, or look for the text GetActivityInfo in your add-on folder files.