Tes4Mod:Troubleshooting

This is just the meeting place for all of the troubleshooting pages, but it has a few suggestions for helping yourself as well.  The more information you can gather about your problem, the quicker a solution can be found.

Facts & Tips
There is a hard cap of 255 active plugins.
There is a soft cap of 300-400 total BSAs and plugins that can be installed in your data folder (before Oblivion starts acting "funny.")
CTD on Startup usually indicates a missing master or a bad Oblivion.ini setting.
Whenever troubleshooting crashes, try regenerating a fresh Oblivion.ini.
Reinstalling Oblivion will not overwrite an existing Oblivion.ini, so clear it out along with the My Games\Oblivion folder for a clean sweep.
Wrye Bash users should rebuild the bashed patch after all load order changes.  Not doing so may result in CTDs.
The GOTY edition of Oblivion is already patched to the latest version.
It is usually best to post your load order with your mod-related questions.
The list that BOSS prints is not your load order.
Check the BOSS log for compatibility information and other suggestions.
FormID Finder and RefScope can be used to track down missing meshes and textures.
You need to use some form of "archive invalidation", preferably "BSA redirection" (included in OBMM and WB; see BSAs and Archive Invalidation) if using mods that replace files in BSAs.
If you cannot open the console for some reason, get the Ring of Console mods (linked under "Related Resources".)
Win7 and Vista users should either install outside of the Program Files (x86) folder or turn of the UAC for the Oblivion folder.

A Troubleshooting Checklist
Regenerate your Oblivion.ini
Make sure you made the DarNified UI or DarkUIdDarN font changes if not using OBMM or after regenerating a new Oblivion.ini
If not using UI, make sure the game is patched to the latest version
Use utility mods and TES4Edit to narrow down possible candidates for the problem
Run your load order through BOSS and hand-placed unrecognized plugins, or otherwise made sure it is correct
Check the BOSS log for suggested changes
Make sure that you have no missing or delinquent masters
Make sure FFDShow set to ignore Oblivion, sound and video-wise
Try a codec reset utility
Check out the "Problems, Causes, and Solutions Library" (PCS Library)
Exhaust the resources linked below
Update your mods
Update your drivers
Test without mods
Rebuild your bashed patch after making changes to your LO
Rerun TES4LODGen after making changes to your LO
Try a clean boot
Make sure BSAs are being loaded
Download at least the version of OBSE specified by your mods
Make sure BSA Redirection (archive invalidation) is turned on in OBMM and/or BAIN
Do a clean update of any mod(s) recently installed, if the issue seems to be mod related

Other Quick Tests
Test for bad spawn - crash is area consistent.
In order to get back to the test area quickly, first get the ID for an interior nearby (or the current one.)
Open the console.
Enter "TDT" (toggle debug text).
If the cell ID is not in the upper-left corner already, use the console command "SDT 0". 
:Note: link listing all of the SetDebugText pages can be found in the "Related Resources" section
Use the console command "COC Testinghall" to get to the testinghall.
Wait 73 hours (or more, if you extended the cell respawn time.) 
:Note: 1) The default cell respawn time is 3 days (72 hrs).  2) You have to wait at least one more hour after the default time for cells to reset.  3) You need to be at least two cells away from the cell that needs to be respawn for the contents to be respawned.
Use "COC  " to get back to where you were in the beginning.
Test for bad save data - consistent crashes
Rollback to an earlier save and go back to the same place or do the same thing to see if the problem is resolved.

Useful Info When Asking for Help
Mods
Test the problem without any mods installed.  Remember the mods that do not have plugins.
The fewer mods you can narrow down as possible cause.
Post your load order, preferably with Wrye Bash.
Post your OBSE version and plugins as well.
Use FormID Finder, Kuertee's Actor Details and RefScope to track down the owners of meshes, textures, etc.
Try console commands such as toggle AI (tai) and toggle script (toggle script) to try to narrow down the nature of the issue.
Possible hardware or software-related issue
Post your Dxdiag
Post your load order if running any mods.
Crashing
Be as specific about the crashes as possible (i.e., common location or action.)

Asking for help
Please post long lists in spoiler tags  
Is the problem specific to a mod or group of mods? 
:Note: Many utilities have a thread too
Do not assume.  Test the game without mods first.
Try to post in the relevant mod(s)' thread in the Mods forum before starting your own thread.
Give them some time to get to your request.  Most users do not hang about all day.
Search for the mod(s)' threads in the BethSoft Mods forum. 
:Note: Try using fewer words or more-specific names to find the thread
Post your load order along with your question, preferably with Wrye Bash.
Is the problem mod-related at all?
Do not assume.  Test the game without mods first.
Post in the Mods forum with your load order.
Does the problem persist without mods or are you running the game without mods?
Post in the Hardware and Software Information forum.
You may need to post your dxdiag.
Utilities
A number of mod utilities have current threads.  Try to find those first.
Include the exact error message (if it is not too long.)

Related Pages
BSAs and Archive Invalidation
PCS Library  (Problems, Causes, and Solutions Library)
Utilities and Mods for Troubleshooting
How to Post Your Load Order
How to Regenerate the Oblivion.ini
Stabilization Mods

External Links
ATI Drivers
BethSoft Unofficial Technical FAQ - Pinned in the Hardware and Software forum, a great troubleshooting resource
Category:Troubleshooting - TESCSWiki
Clean Boot Windows XP
Clean Boot Windows
Direct X 9.0c
DXDiag Interpretation Guide
Glarthir Causing Crashes? - BethSoft thread, discusses crashing between Skingrad and Anvil
K-Lite Codec Pack - This codec pack is safe for Oblivion, and it can be used to reset and/or fix your codecs.
NVIDIA Drivers
NPC IDs - OblivioWiki
Photobucket - if you need to upload screenshots...
Ring of Console - for users that cannot open the console normally
SDT Pages - Set Debug Text (SDT) page descriptions
Technical Support - UESPWiki
TES4Mod:FCOM/FAQ - UESPWiki
The Elder Scrolls Texture Guide - TESTG has common terms, explains graphic file concepts, and lists utilities and links for texture replacers for all TES games
Tracking down a corrupt spawnpoint - BethSoft thread
Unofficial Technical FAQ - Slow/Frozen...animations, Jittering Doors... - BethSoft (pinned) thread
Windows Vista - TESCSWiki; help with UAC and related issues, applies to Win7 users too
Wrye Bash - Essential tool for resolving conflicts between multiple mods in a lengthy Load Order, with many other functions including management of the Install Order
Wrye Bash Pictorial Guide - WBPG is an annotated graphic guide to the Wrye Bash interface.  It is intended to get a new user functional quickly
Troubleshooting