Sorry if this information is elsewhere, but I can't figure it out for the life of me. All of the mod installation guides I've found reference an ../Documents/OpenXcom/mods folder to put my mods into, but when I did so it didn't see any of them. I then read that if that folder is missing (wasn't for me, but I thought maybe it was broken somehow) that running the game would create a new one; well I deleted the folder that was there, but it didn't create a new one after running it. I did a complete re-install of OXCE+, clearing out the old OpenXcom folder in the Program Files (x86) folder and created a new one, copied the OXCE+ files into it and then the OG files, but running the game again still didn't create a new one.
Possibly worth mentioning: I have two drives on my computer. One is my SSD, which is the C:/ drive and where the program files are being installed, but my Documents folder is on the hard drive, which is the D:/ drive. I suspect that could be part of the problem, but I wouldn't know how to fix it.