It looks like at some point the thing spawning it lost the requirement to check against. Should be fixed in 6.4b and hopefully I'll be able to switch over to a system that doesn't have this problem. Because the same thing happened with the sword in the stone.
The free version is always 1 month behind. If you want specifics you can check through the changelog for each version, basically 6.2 had a lot of bug fixes and optimization.
I believe its a bug that happens based on how certain modifiers stack. It should be fixed in 6.1 and onwards, however you will need to restart a save. 6.1 is the new overworld though, so its a perfect time to restart.
dang, sorry to hear that. Not sure what else I can do to fix it, and as far as I've heard youre the only one with this error. Have previous versions worked for you? Also your file says your missing a DLL, try running the prereq setup