I don't know how active this place is anymore, but I don't know where else to bring this.
I bought Skyrim:Legendary Edition on Steam about a month ago, and all three DLCs have worked like a charm. Since then I've been adding mods to my heart's content, until eventually I outdid myself. Constant CTDs and freezes led me to delete all mods I had installed, save for SKSE, since it was a pain enough to do the first time. After that I took a break for about a week, spending time prioritizing what mods I really needed. When I went back in, the first thing I did was set up SkyRe and all its requirements - yes, all of them. Except, apparently, Dawnguard and Dragonborn. Which is kind of a problem, considering I own them. Before deleting all mods, SkyRe was working perfectly fine, as was the ReProccer.
All three DLCs are considered "owned" on my Steam account, and right-clicking Skyrim -> Properties -> DLC has them all checked off. Unchecking and rechecking them does nothing; restarting Steam and my computer does nothing. I also tried entering "help dawnguard" into console just for [censored]&giggles, but nothing - it's simply like they never existed. They don't show up in Data Files, and the only solution I found to a similar issue was to copy paste some ShowData 1 thingamajig into the SkyrimPrefs.ini, which didn't work for me (nor, from what I could gather, for the persons originally provided with that solution).
I'm fairly new (read: oblivious with) PC gaming, so perhaps I'm missing something obvious here. Thanks for any help&sorry for any trouble ^^