Same issue, though not an ironman save. Game cashes once it gets to 2226.04.01. Have tested going back to manual save just before it happened (I had just declared war, and saved before doing so) as well as two previous autosaves, along with various actions (such as cancelling construction or actions). Nothing is ticking over (research, construction, pop growth) as far as I can tell. In all cases crashed on the same day. Also tried deactivating my custom namelist mod. I also tried uninstalling and reinstalling the beta patch. I started this game last night with the beta, and haven't had any crashing issues until now.