I "fixed" this for two friends by just playing. I got more weapons from drops and also took a wapon from the warehouse and got Liz to enhance it for both games. After that they both could go into enigma orders again without crashing. not sure what it was that fixed it (since i copied the exact steps the second time i did it, but the game sorted it out both times. I also heard some one else fixed this by adding a "fake" paragon weapon (paragon weapon with no stats) through cheat engine. however he also let in-game time pass by while trying to figure out how to add the weapon. He had to get the fake weapon from his warehous and updated his inventory. So either you just need to let some ingame time pass or you need to "update" your inventory with new weapons. So all isnt lost even if you have no backup save.