I know this topic is old but if anyone has similar problem it might help... Suddenly I had same problem. I tried all those things above but none of them help. Maybe not completly not helped but just in case I deleted skee64 files (dont mistook with skse64). One file is located in Documents\My Games\Skyrim Special Edition\SKSE and the other in game folder - data - skse - plugins. Don't delete skee64.dll or game won't launch. Then I launched game from steam (not skse), loaded last save that crashed before when loading with skse, did hard save (esc key - save - new save), exit game and relaunch but this time with skse. It worked.
