I click skyrim, the play/options/data files/ interface box opens up, I click play, the box closes and nothing happens. Skyrim doesn't boot. I was told that after a recent patch, in order to fix this, you had to go under skyrim properties in steam and verify your skyrim save cache or something. I did that, tried it again, it didnt work. I unloaded any recent mods i downloaded, nothing seems to be working.
I had a similar issue. I used 9-10 mods, worked just fine, then i added 1 more mod that made my game crash. I deleted/unsubscribed to that mod and the game still crashed. I had to remove all my mods before the game would start and re-install all my mods one by one.
Some of the mods i used at first (that worked just fine) still make my game crash if i try to use them. Really annoying considering that one of them was a playable race mod and since i couldn't use it anymore i had to start a new game.