Greetings,

So. I've got this save here...and after this exact turn, on turn 306, the game slowly, but surely, breaks. Lum3.zip

After Turn 305:
-No saves made after this turn will load. Saves can be made, but all saves attempted to load after this turn become stuck on Launching Game. Endless Space 2 will still function as running, but indefinitely hang.
-The System Management tab breaks in one of two different ways: it will either become completely blank, or it will be view-able, but only alphabetical sorting will work. Sorting by happiness or any sort of income will not function properly if it breaks instead of being blank.
-The game is playable until the next election (End of Turn 320), despite being unloadable. At the point of the next election, the game will not allow you to progress past the election screen. Even though the game runs in the background, the election screen or the Skip screen will simply feedback into each other, preventing further play.

-Diplomacy with the Orange Unfallen or Pink Sophons factions (They are an alliance) becomes impossible to initiate after turn 305. All terms selected will not appear in the contract window for these factions, even though any terms clicked on will elicit an opinion bar response. AI Diplomacy becomes erratic in general.
-The Red Sheredyn's faction name eventually breaks, returning some garbled AI% sort of name.
-Winning the Academy quest for the Rejuvenator's will not trigger an achievement through Steam. I'm unsure if this is related to the broken turns after 305, or if the achievement is simply broken.
-Fahemmn Nutharr II's planet thumbnail portrait is white. Not related to the turn issue, and minor, but while I'm pointing things out I figured I'd mention it.

Save is Huge Map, Endless difficulty & Length, 8 AI Opponents, as Lumeris.

This is indeed an interesting... case study to say the least :)

Thank you for sharing we'll look into it!

Cheers,