In the absence of any other advice from folk who may be able to put their finger on your problem. Assuming that if you have the latest Steam patch installed from yesterday then you also have the updated NVSE to go with it Assuming that the ctd occurs randomly and not in the same quest, place, action or item etc, the fact that you are encountering CTD after a couple of hours and not sooner suggests to me that it is not mod based. Have you tested/monitored and ruled out the possibility of hardware faults (graphics card) or possible faults caused by software running in the background? Check your system by running NV in vanilla and ensure there are no ctd's - real pain but I guess you need to be certain of this To check mods I can only suggest: Add mods one at a time and play long enough to check all is well or until you hit a snag Ensure each mod is installed correctly with any compatabilty patches, FOMM BOSS (which you are doing) to check load order and archieve invalidation toggled. Mods that change game weapon balance etc might be influenced by the new patch and need updating - do not know - needs verification. You probably already know all this but hope it helps anyway