I am reposting this as a separate thread as I have seen this over and over and would like a simple quick reference out there to help people.

There is solution but it's a pain.
You will need to:
1. Empty your inventory into personal or vault storage (latter preferred)
*please note you will NOT likely be able to move the bugged item at this time!*
2) Exit your game
3) Delete the game save file as it has become corrupt. DO NOT DELETE YOUR GAME!
4) Re-enter your game.
5) Move the bugged item to storage, sell or use.
6) Customize personal settings, volume, aim assist, slash commands, etc.
7) exit the game again and restore licenses from the sony accounts menu.
8) Re-enter the game and return ONLY WHAT YOU REALLY USE (no outdated items or items you do not plan to sell.)

If this process does not resolve the issue you will need to file a support ticket.

Easy fix is to make a backup on the Sony server once resolved of a "good " game save file, which then can overwrite the bad without having to re-enter everything.
Please note that if you play on both NA and EU servers you should be doing this anyway and maintaining only ONE save file as there is an "unconfirmed by Trion yet tested and confirmed by me" series of bugs that can occur if you have one of each visible to Sony. I'm going to try to get with a dev shortly to be given permission to discuss this more thoroughly, as I think it's causing far more issues than even I've noted, but for now It's something I've agreed to not fully explain until they can confirm.

The problem appears to stem from an update where more items were introduced than could be calculated in line items by the inventory system so it loses count of the "position" of specific item types and gets the codes mixed up. It may also be trying to play mix and match with a previous version before specific items were introduced, causing duplicate name space handlers. (this is only a suspicion though based on recent errors I have been receiving regarding false version conflicts.) see here for what I am referring to: