How to get this weapon again?! The first time The chest appeared in Concordia I didn’t take it, and now I’m in the mission science and violence and I can’t get through the Mini-Boss Battle against the X-STLK-23, I’ve already tried getting out of the game and going to another location and the chest with the moxxi doesn’t appear, what can I Do, I can’t keep going on with the game cause of that mission
You can only have one per playthrough so TVHM is the next time you can get one. If you have trouble fighting the boss you can post your build and/or you can farm for a good shock weapon/grenade to strip its shield.
This was apparently unintended behaviour and got patched out several years ago. As TempNight suggested, farming up some decent shock gear is one approach. What level is your character, and what level is the mission?