I installed Gunmod's Scriptorium which I already had on my old pc for years, therefore some experience when using. But this time I wanted also to add some aesthetic lighting on my new pc which goes with GunMod, you know the ones with Lighting.txt file. The first lighting was extremely laggy whenever an active family was present on the lot, the sims look darker and the floor was dark despite the room having windows. The second one I tried was working fine but it made CAS extremely overexposed. I overwrote my lighting.txt file without thinking twice so I wish to either get the default one back or try a working mod. I tried pasting the lighting.txt from other EPs but it crashed my game in startup. What do you think I should do?

You know why you're always asked to back up files before putting in the modded ones?
That's right!
Maybe now you'll remember it for the next time

I'm sure you can get the one you had from the Scriptorium back by downloading the "manual installation" files and digging around for the lighting.txt file. If that's the one that worked for you before, you don't actually need to go back to the default file, especially if you plan to use a different mod later.

I have seen a few lighting mods (or camera mods?) that include handy backups of the original files, but it didn't look like either of those links had any. I would've included the file, but I'm a bit unsure what I have at the moment (I haven't gotten as far as to install any lighting mods - I used to have Gunmod's 2.4 on my CD game, but copied over my saved game to the UC version, and figured out I had my old camera mod and a bunch of other things, so now I don't know what's managed to find its way into my game). Plus, your game setup could be different from mine (CDs vs UC?).

As for the mod itself, make sure you've read everything about the mod, and that you have the setup required. If the setup is for all EPs and/or the UC, make sure you have that. If you lack certain EPs, the mod may not work properly.

If you have the UC and reeeeeeally want the original file back, you can reset your game via Origin, BUT be prepared to first backup everything you don't want to lose in both the Program Files and the Documents location for your game.

Spookymuffin's light mod includes a backup of default Maxis lights text file.

https://simfileshare.net/download/322662/

@simmer22 and @jotaerre I actually found the default files but also reinstalling Scriptprium creates their own lighting file. Also, GunMod offers default files in his post. For some reason my CAS is still overexposured although I have GunMods lighting only installed which worked perfectly on my old win7 pc. The game isn't laggy anymore btw. If it can't be fixed for Ultimate Collection on Win10 than it's okay. I use bodyshop for creating Sims anyway.