In a recent playthrough of the first game using patch 1.3.6 from Nuclear City, when I tried to recruit Tycho, I got a message saying I already had an assistant as I had Ian. I was using Gifted and had my charisma at 2. I had Sfall 1.18e with the patch as that was the latest version that was official.

What caused this problem? Has anyone experienced this problem and what caused it?

Charisma is the limiting factor when your character attempts to influence others.