I’m not sure when this happened, but when I logged into Steam today, I was advised Conan Exiles needed to be installed. I’ve been playing this for a long time.
Does anyone know if this is about a recent update?
After I reinstall it, I’ll see if my save solo game is still there or if I can resurrect it.
It turns out to be caused by a recent update, but reinstalling the game to the same drive, which recognized all of the old files and it’s restored. 
Strange issue, i didn’t have it, but glad you got your solo game back
Thanks! This has happened to me a couple of times as the result of updates. I think it happened once in ARK.
strange. I haven’t see that either. The big pet update should be coming in a few weeks but we haven’t had anything too big in a while.