Recently downloaded Skyrim SE from Steam. It works just fine with no modifications. When I add on any single mod it won't play after the initial loader. I don't have many mods, maybe 30, and I have SKSE, the NMM, and LOOT all configured and LOOT says there are no issues with my mods or load order. It boots fine as soon as I disable all mods, but won't load if any single one is active let alone more than that.