The rogue agents in Warlords were a little bit too effective in stopping the player... (At least they don't ability spam like a certain boss did.) Could be any number of things, unless it could be narrowed down as more likely to happen on certain areas of the map or around certain encounters it's pretty hard to specifically get a lead on what is causing things to crash plus open world and random encounters and events it could even be some slight glitch or other problem. (What was that one crash bug in Half-Life 2 some QA tester found again, run in a circle 40 something times in one area of this one map and then one more and it would immediately crash. Somehow someone found that.) EDIT: For the game specifically there used to be a few areas with missing geometry and see through little holes and such take that with culling or lack thereof or hitting some math or other error and some small pixel sized hole could be messing everything up. Not entirely likely to be the case but part of the nature of how difficult it is to go over a large map and open world game and check on everything. EDIT: Post TU8 there was this one skyscraper in the Washington map that would fail to render properly from one side so you'd see right through it and part of the rest of the map, didn't crash but caused a hefty framerate hit for how much the GPU had to be doing suddenly that shouldn't be visible normally though usually these glitches are smaller or you just have minor clipping or floating objects that look off but don't do anything problematic. (Well other than wonky collision boxes and animations and yeah that didn't count as being in cover apparently..) Probably fixed now, I stopped playing shortly after that was released and wrapping up the Warlords expansion and content.