I'll piggy back on this issue.
I've experienced the same issue. Was playing a game several hundred turns in on an insane map with no mods but custom races from Steamworks. Within a few dozen turns of loading the game post-hotfix yesterday it would hang any time I tried to clear any heavily defended precursor anomaly.
Thinking it was just a lost cause because it was a 1.8 game and not a 1.8-hotfix game, I tried a new game.
This game hung 17 turns in as the focus came back to me. The turn indicator stopped at "Starting new turn". Completely frozen game. This was insane with ~35 races including some of the Steamworks ones.
I cleared out all Steamworks content and started another insane game with just races created through the in game UI. This game also froze at 17 turns.
I created a ticket and attached both save games for the 17 turn games.
Ticket #VCB-542-56980.