Hi everyone.

I am totally at my wits' end with a really persistent crash whenever I enter Frostcrag Spire. The loading screen pops up and the music continues to play, but the bar doesn't move and there are intermittent popping sounds from my headphones.

So far, to troubleshoot, I have:

• Disabled all mods except for Oblivion and Frostcrag
  
• Recopied the Frostcrag files (bsa/esp) from a backup Oblivion directory
  
• Tried copying all my mods from a previous installation of Oblivion (thinking that maybe I had edited the Frostcrag esp in the past, and it needed another mod installed to run)
  
• Going into the construction set to try viewing the areas which crash and looking for conflicts - this doesn't work because the set also crashes when I try to enter the rooms
  
• Tried using the "coc" command rather than the doors

I really don't know what to do. I don't really want to abandon this game as it's my first time on OOO and I've spent ages installing loads of graphics mods and whatnot.

The areas I cannot access are "FrostcragSpire01" and "FrostcragSpire03" - "02" works fine, as do the outside areas. When I try to load these areas in CS, I get this error message:

"Error inflating ZLib stream for file "Meshes\Architecture\MagesTowerLevel01.NIF"". If I continue, the CS freezes.

ANY useful help is very much appreciated.