Critical error:
When I try to load an earlier save in 6.036, I get a "Client Receiving Data Error", followed by all of the Harvesters in the galaxy being "reset", all Fallen Spire stuff disappearing, and all unit caps returning to single-homeoworld levels.
Edit: All the wormholes went away, too. Interesting universe... I couldn't lose anymore!
I've attached a save, plus the ArcenDebugLog.txt and ClientReceivingData.txt logs. There was nothing in the UnhandledErrors log.
This happened in several saves, but not in others from earlier in the game. It may be related to the late-game Fallen Spire stuff - the cutoff point seems to be somewhere around City 5/Exogalactic Transceiver.