Yeah, I am running the Enhanced Edition Version.. only one I still have.
I followed your steps and I deleted TobEx, Fixpack, and Infinity Animations as well as the copy of BG1 UB, then I re-extracted the BG1 UB, cut the Setup file out of the BG1 UB folder and put it back in the folder with the CHITIN.KEY file, ran it and got the same thing.
Maybe one of the other MODS I installed has changed something (BG1 tweaks, BG2 Tweaks, IWDification, Divine Remix, WeiDU, Kitpack, Autoroller, Widescreen, or the psionics one), or ToBEx, despite not running to completion, managed to mess something up?
I am starting to think that I may have to do a full clean install of the game and try again. Maybe I installed something out of order?. Seems like it might be the only recourse as it still says the same thing about that [STUP-BG1UB.TP2] File not being found.
Either way, I am still very thankful for the time you have spent on this project and even more for the time helping me. Just telling me that TobEx and Fixpack wouldn't work with EE was helpful, as the only reason I was trying to install TobEx and Animations was for IWDification (said it was needed to let you see more than 24 spells on a page) solved a ton of headaches lol. More thoughts, I am happy to hear, though I am almost sure that the next step you say will be full clean install.
Have a good Evening.