It only seems to be when I'm indoors, but as I'm going around everything will go very dark suddenly. Sometimes it is difficult to see, and then when I look to the right slightly all of a sudden it's nice and bright again. I am using mods such as Realistic Lighting and ENB but this has only started recently. It may be something to do with the tweak I used from Nvida that increases the grids loaded to 7 but I don't see how that would affect lighting.

Shordammitsomuch... Do not fiddle with uGridsToLoad. You are playing Russian Roulette every time you load your game up with any uGrids setting other than 5.

That guide is wrong. The author insists he's right but he is wrong. Time and time again, uGrids fiddling has proven to cause instability in the game over the long term. Leave it at 5. Even just bumping it up to 7, you are nearly doubling the number of cells loaded. 9? 11? Far far sooner than later will problems occur.

There is a procedure you will have to follow for getting it back to 5. You can't just set it back in the INI and be done with it... unless you have saves recent enough back that were before loading the uGrids Russian Roulette revolver that you are willing to fall back to. Any saves you made while uGrids was not 5 will not load if you just set it back in the INI.

Sorry to be so blunt about it, but it cannot be impressed enough that uGrids tampering is a very bad idea.

Anyhoo, for your problem in specific, what you seem to be having problems with sounds like is adaptation. Basically, it simulates the way the eye adjusts to brightness, but if settings for are not calibrated right, it can become a problem as it has for you. Does the problem disappear if you press Shift-F12? That keystroke toggles ENB in-game. Does it disappear if you unload the Realistic Lighting module?

I think it must be something to do with uGrids; the last two fixes you suggested didn't work. Thanks for telling me about uGrids. Wouldn't really be able to change my mind about it much later as I think the page said that it corrupts your saves!

:l Not happy with whoever wrote that tweak guide; about two hours of gameplay has been corrupted now. Is there any way you know of to fix it?

I also have grids loaded set to 7 with no problems but, I do not have any ENB or lighting mods.

Um I think it might be something to do with something completely different, actually. I was just playing Fallout 3 and the exact same problem occurs. I'd bet it's in New Vegas as well. I tried using the 'Restore' option on Nvidia control panel and that didn't work. I have certainly not changed anything on Fallout as I haven't played it in a while. I could be something to do with my new monitor which I got very recently, although I have no idea how that could affect it.

Never mind just solved it. I had a setting engaged, Dynamic Contrast which messed things up for some reason. Still, if anyone knows a way of fixing those corrupt saves on Skyrim that I mentioned due to uGrids that would be very much appreciated. Thanks for the help.

You have no problems yet. You will. Reduce it back to five now before it does become a problem.

I did some reading around, and the very same guide who gives the ill-advised "It's okay" advice on tampering with uGrids to begin with also provides a means to undo the damage:

• Backup SkyrimPrefs.ini, Skyrim.ini and your Skyrim ‘Saves’ folder.
• Right click on Skyrim.ini in My Documents\My Games\Skyrim and uncheck ‘Read Only’ in the file’s properties.
• Load your last save game.
• Press tilde on your keyboard, most commonly placed directly to the left of ‘1.’ If it is elsewhere, the keyboard symbol should be ` or ~.
• In the now-visible in-game console type setini “ugridstoload:general” 5
• Hit Return on your keyboard.
• Type saveini
• Hit Return on your keyboard.
• Type refreshini
• Hit Return on your keyboard.
• Close the console using tilde.
• Create a new save game.
• Exit Skyrim.
• Delete Skyrim.ini in My Documents\My Games\Skyrim.
• Reload the Skyrim configuration tool. (MADCAT NOTE: I presume they mean the default launcher, as that's what generates new INIs)
• Close the tool.
• Re-tweak Skyrim.ini if necessary (and SkyrimPrefs.ini if it has since been modified).
• Reload Skyrim and your most recent save.
• Enjoy the game.