Title says it. Let me try to give you as much info as possible so I can hopefully get the help I need quickly. I was using some mods, all of which worked great. Then I decided to try out "All Natural" which requires Wrye Bash (which I am trying to learn, but I'm new at this and it is not a user friendly program). I followed the instructions in All Natural's readme as well as I could, in addition to http://amito.freehostia.com/Oblivion/OB-mods-Part2.htm instructions for building a bashed patch.

All Natural's readme said to "Rebuild your Bashed Patch, selecting “Import Cells” from “All Natural.esp”. Also select “Import Cells” from “All Natural - SI.esp.” & “All Natural - Indoor Weather Filter For Mods.esp” if you are using them." I could not figure out how to do this, so I just stuck with the instructions I linked you to above.

I sort of stumbled through as best I could, and I figured worst case scenario was All Natural wouldn't work and I would have to settle for something easier to install. Turns out I was wrong, now Oblivion will not start at all (whether launched through the OBSE loader or the regular Oblivion launcher). I get about a second of black screen when I start it up like it is about to work and then it just disappears and *POOF* I'm back on my desktop.

Can I undo the bashed patch and put things back the way they were when they worked? I'll cross the All Natural bridge when I come to it, I just want Oblivion working again with the mods I had.

What could have caused this problem? Please help!

Deactivate All Natural - Indoor Weather Filter For Mods.esp. It should have a circle in the checkbox after you deactivate it.

Wrye Bash isn't that hard once you use it a few times.
It's a masterfully done program overall.
A lot of its features operate by Right clicking an area in a window or on a tab or particular column header.
The instructions you followed, I couldn't find in the link you posted but , I'll give it a try.
If you are on the mods tab of Wrye Bash, look in the lower right corner when you click on a mod in the mod list.
In that little square in the LOWER RIGHT CORNER if you Right Click and hold there will be a list of "bash tags" that will appear, on that list will be "Import cells" and a ton of other variables and I'm betting it's already checked or Import Cells appears as one of the bash tags in that little window before you have even clicked there...anyways, next-

Look in the mods list on the left side, scroll all the way to the bottom and you should see a mod listed there called "Bashed Patch", right click on it and choose "rebuild patch" step through the check list on the menus that appear and look for import cells, check it and in the other window check the box next to “All Natural - SI.esp.” & “All Natural - Indoor Weather Filter For Mods.esp” if you don't see them listed there either they {All Natural - SI.esp.” & “All Natural - Indoor Weather Filter For Mods.esp} haven't been bash tagged
in which case you should follow my first paragraph, and try the second paragraph we just left again.

In either case your next stop should be Tes Nexus and a copy of BOSS, once installed it will make this process a bit easier and put your mods in the right order and tell you what bash tags to put on which mod.

The reason your game is kicking out without starting probably means one of your mods is missing a "master"
If you click on a particular mod or "ESP", going down the list one by one in Wrye Bash's, Mods tab, mod list.
Look in the little window just Over the bash tag window I showed you earlier, and it will tell you what other mods that particular ESP depends on listed if you see one that's ORANGE that probably means it isn't installed into the Oblivion/Data folder with all the other mod esp's and thus is a "missing master" or ESP/ESM that MOD or ESP is depending on being there.

Read this SLOWLY and have WRYE open and go along with what I've told you step by step, then go to the Wrye thread and get yesself educated. You can't easily run a modded Oblivion without crashing without... Oblivion Mod Manager, Wrye Bash, and BOSS.
Good luck...We're all counting on you. :goodjob:

Sounds like sound advice to me :goodjob:

OT apothekari, did my suggestions on the Wrye Bash thread help you, it's just you haven't been back to it since my last posting and it's moved to a new thread since?

Thanks for the help. I think the problem was actually with COBL, because even after I rebuilt the patch very carefully, it still didn't work. Some of the COBL files got messed up somehow I guess. Anyway, I deleted the ones that were causing problems and rebuilt my patch again. It works just fine now!

Oh yeah!, Big Help, man.
Been enjoying playing and using what I learned to help others, jus' payin' it forward, you good example you! :intergalactic:
I started out killin' time waiting for Nehrim to be translated and the got back into ESIV big time with all the cool mods that have been made in the last year and a half!

Glad to hear I helped a little Capt Awesome, you can thank folks like Artorius and the other great modders here on the site.

You're very welcome , but I am just an ant standing on the shoulders of the giants that reside here.