When gathering all targeting data and switching Revision Zero from normal firing mode to Hunters Trace, the gun won't shoot, can't switch back to normal firing mode, nothing. Basically locks the weapon completely until you go back to orbit or change Revision Zero to a different weapon primary in your inventory screen. I've tested it about 10 times on different levels of targeting data, locks the weapon and makes it unable to shoot every time. EDIT: Added context to title and more info to post.