Tes4Mod:PCS Library/CTD within seconds of entering certain areas

Problem
CTD within seconds of entering certain areas

Cause - Specular lighting
Requirement for specular lighting in the areas, while it has been switched off.

Solution: Workaround: 
Set the variable bDoSpecularPass in Oblivion.ini to "1" if you switched it off before. You can turn it back off after you're past the problem area.

Cause - Corrupted master file
Casual crashes in Oblivion are to be expected, but sometimes the crash corrupts the master file causing exceptional crashiness in damaged areas (and as result likehood for further corruption of the file).

Solution: Workaround:
Be in the first person perspective mode. As soon as you enter the area, look straight down at the floor and run to the desired exit door using your feel (map, hints from the floor looks), without looking up. Of course you can't do much in such areas that way. It can get you, say, across the Skingrad castle courtyard though.

Solution: Reinstall Oblivion. Your saves shouldn't be lost but just in case back them up (My Documents\My Games\Oblivion\Saves) then uninstall Oblivion (with Add/Remove Programs), reboot, install Oblivion again, possibly reboot again. Most likely your savegames are still present, if not, recover from backup. Don't start with a savegame created in the crashy area, pick an earlier one if needed. If you would prefer not to reinstall the game, you can restore your autosave. Go to your Saves directory (commonly C:\Documents and Settings\"user name"\My Documents\My Games\Oblivion\Saves) and delete autosave.ess. Then rename autosave.bak to autosave.ess. Occasionally, the .ess and .bak will not have been generated during the same save, so restoring the .bak will result in starting from 2nd most recent autosave point. For reasons unclear, following the steps in the next Solution will cease corruption of autosave files also.

Solution: Stop overwriting existing save files and avoid using Quicksave. Disabling quicksaves will have a dramatic effect in reducing crashes. Supporting the hypothesis that corrupted saves cause game crashes rather than game crashes corrupt saves, it seems that clicking "new save" everytime will eliminate those pesky "crash on area transition" crashes. Autosave has it's own issues involving scripts that may be running at that moment.  Manual saves only to new files at "pause moments" are recommended.

Cause - ShadowMapResolution change
iShadowMapResolution was changed from 1024 to 256 in Oblivion.ini for patch 1.2

Solution: Open Oblivion.ini. Find iShadowMapResolution. Change "256" to "1024". Close Oblivion.ini and save changes.

Cause - HDR Lighting
HDR lighting is enabled on a graphics card that doesn't support it.

Solution: Just go into video settings and turn HDR lighting off.

Cause - Internal Shadows
Internal shadows are turned off. Sometimes going through a door will immediately CTD.

Solution: Turn on Internal shadows.

Cause - Broken mesh or path to mesh
This is usually due to attempts to modify some item that were less than totally successful.  This may be an error in the mesh itself or saving the mesh with an absolute or explicit (i.e. "C:\Oblivion\Data\ ") rather than relative (i.e. "..\ ") path.

Solution: Fix the broken mesh or path.