There's the recent spate of frozen, passive creatures too which only start appearing after guides were created for editing the save files.
I had the issue with frozen creatures before my first attempt at editing a save file a few weeks ago. And my first successful attempt at loading an edited colony save file was one week ago. So I think the frozen creatures appearing after the guides appeared is a coincidence.
I'm not sure if issues with edited colonies can really be classed as bugs - we can't really be in the business of supporting happenings outside of the set game saving system.
I understand that in most cases you can't do much with an issue that happened with an edited colony. I do not expect anything to be done with this, but I will still share my thoughts on this issue. So far, these are the different scenarios I can think of:
1. It was not caused by the editing. Then it should be triggerable without an edited colony. (An issue)
2. It was caused by a bad edit. (I think I only changed the "IntProperty" value stored of the "...Improvement". But still, errare humanum est.) (My fault)
3. It was indirectly caused by the editing because it elevated a/multiple upgrade values to unreachable levels. (Not an issue)
4. It was indirectly caused by the editing because it elevated a/multiple upgrade values to high (but not unreachable) levels. (A rare issue?)