I'm getting repeated Error in CheckForRuins in my current 5.52 game. Error 3421: Data Type Conversion error. There is a planet that I believe will contain ruins, but I am not currently in a system with one, so my guess is that the defenders of said planet are managing to cause the problem themselves, or possibly with other outside help.
EDIT: I think I now have a little more data on this bug. I am in combat with a squad of missle-throwing ships (a few 12000-ish tons, a few 6000-ish tons) that have run out of missiles, allowing my laser-only ships to close to range. For each shot that hits and does damage, I'm getting one of these CheckForRuins errors. This is in addition to often getting them when my time increments are shortened due to NPRs fighting each other.