Stardock, could you please make a sticky in the FE Support forum saying that 0.77 saves that have techs unlocked from quests currently corrupt saves after getting them, and that this is fixed in the next patch? It is being reported a lot, and I don't know of any other current reason for corrupted saves apart from techs unlocked from quests (and maybe some saves when low on memory, however I've found in this case it just crashes without making a save). It would be a huge deal if you mentioned the save corruption bug details and that it is fixed for the next patch in a sticky in FE Support! 
