I recently downloaded sea of destiny plugin, and per its instructions, turned off the offical made siege at firemoth plugin. Manual said it would conflict. upon turing it off, and Sea of destiny on, i cilck new game. I promptly get an error message saying it cant find a cell for 'fort firemoth region'. How to tell the game to recognize that fort firemoth is no longer there?

I think you cannot be playing a new game. This error occurs whereyou are playing an old game and firemoth is on your map and in the journal. When you start a new game pre chargen you would not get the error. AFAIK you can just ignore the message but the firemoth landmass willl still show on the map.

BTW that particular mod is one of the least satisfactory quest mods available IMO. Read the spoilers thread for better ones.

I tried starting a new one you mean i cant have any savefiles that had the firemoth journal entry? id have to delete em all? as for ignoring it, no i cant, when the error comes up and i ackknowledge it it closes to desktop. Its not the bootup errors, its when i actually click 'new' that i get a windows box saying it cant find it.