PCS:Oblivion is crashing when trying to save by any method
Oblivion crashes when you try to save via the console, a save key or any other method.
Causes and Solutions
Cause 1 - Bad Spawn
This sort of consistent CTD when trying to save can be cause by a corrupt spawn.
Solution #1: Just wait out the cell respawn time (+1 hour). The default is three days; therefore, if you have not changed Oblivion's cell respawn time, you need to wait 73 hours to reset all spawns.
Solution #2: A quicker albeit a little less safe option, would be to use the console command
killall. It kills all actors in a reasonable radius. This might be a good way to quickly check if a bad spawn in the area is indeed the cause for this problem, however.
Crash to desktop