I recently started seeing this message as well.
There are already a couple threads about it, but it seems to be a developer’s tool that is being activated by new issues specifically related to SOLO play since 3.0 . I only started experiencing it yesterday following the Version 1.81 Conan Hot Patch. I can also confirm that Restarting and shutting down the PS4 do nothing to resolve the issue.
I now get this error every SOLO game i play, I simply hit the accept button and see no ill effect to my game play as long as I avoid using sorcery in general, which at this time currently locks up Game play in SOLO MODE at a very high percentage of use of Arcane Staff use.
Here is the original solution I was pointed to a couple of days ago, when I posted the same bug.