Has anyone had an issue with skintone changing? All of my sims with S3 skintone suddenly changed to S1 or S2. I have default replacements and I don't know if it may cause the problem. Hoodchecker is not showing any problem with corruption

I've never had that issue, but I have a few thoughts on it. I use a default skin replacement by jwilson5 as I have for years and it features an option for variety. The tones were made in pink, light, mid, tan, dark tan and dark And each of those is available as the default replacement for several skintones ( excluding pink and dark). The mid, for example is available as S1 or S2. The dark tone is available as S3 or S4 and so on. If your default replacement set has options of that sort perhaps you've moved a dupe skintone ( but one that now defaults as both S2 and S3 and S1 I guess too, lol), and that replaced/overrode your other defaults. From your post it does sound like all 4 tones were previously showing up correctly.

My only other thought is have you installed new cc, particularly sims as those frequently have attached skintones one of which could have been a default ?

All my skintones were just fine before. I have this default replacement v2 and I never changed it - https://gardenofshadows.org.uk/gard...30843#msg630843
I don't know if it's this replacement in particular or my save being wonky. And I didn't download any sims or skins I've always had only these...

Defaults don't attach to downloadable sims, so that shouldn't be a problem.

Geneticized skins can, though. They can also mix-and-match (quite literally) with default skins depending on their genetic value, so if you've accidentally downloaded a geneticized skin set (or just a few skins) instead of regular custom skins and suddenly find (new) sims being born with other skins, or sims getting other skins in CAS than your defaults, then this is most likely the issue.

Skins suddenly switching to other skins, though... That's kinda weird. Have you done any shuffling or renaming of files in your Downloads folder recently? For defaults, whatever is read last by the game is what shows up, so if you've had other default skin files than just the 4 defaults needed, chances are any moving around and renaming can change the file order so other files show up.

I also don’t have any additional skins except for those default replacements. And already existing sims skins changed and it’s every single one that had S3 skin. I checked their DNA in SimPE and everything seems to be in tact. However I did use renaming tool to remove any brackets etc. I’ll have a look at it

Chances are either another default skin or a geneticized skin that's in the range between S2 and S4 has snuck into your Downloads folder somewhere.

You can also check if there is something going on just by pulling out the 4 default skins you use, and seeing if the sims go back to using EAxis skins. If they don't, you have other default skins hiding somewhere.

You can try to do a 50/50 search to find the item (that's honestly the easiest, since this is one of the cases where either the item is there or it's not). Make sure to keep the 4 default skins you use out of the game through the searching process, so you know when you're back to just the EAxis skins. That way you're sure you have a "clean slate" when you put the default skins back again.

Fixed it. It was because I removed brackets from a file name. Thank u for help everyone :lovestruc

Chances are you picked up another skin tone and it's affected these. Just because you didn't go and download and install it purposely doesn't mean it didn't sneak in somehow, these things happen. Years ago I had sims with 4 nipples and you can bet I didn't purposely download something to have that happen. I had to do a 50/50 hunt to find the file which ended up being one of those unnamed files full of odd random letters. Unless you have not downloaded or installed a single piece of CC or sim since you installed that default skin then chances are this is a CC issue.

Make a full backup of your game and put it safely to one side. The entire sims 2 folder.
Start testing.
Make a new sims 2 folder by right clicking your normal folder in Documents, select rename and add a word to the end. Load the game and it will make you a second fresh sims 2 folder. How does this vanilla no cc game look? If everything looks normal then your game files are fine and you can know you have a cc problem. We have all had them and they are a pain but they are solvable.

Exit the game and add your skin default and load up again, is it working?
If so it's time for the 50/50 hunt. Make a folder on your desktop and use names to keep everything you have tested organized. Go over and copy your download folder and split it in half. So 50% in one folder and 50% in a second folder. Don't forget to check the Saved Sims folder since CC could also be lurking in there.
try your default with one half of your normal downloads, then try the other half and try it with the cc from your saved sims folder. The clashing CC will be in one of those folders you just tried. Put the folders that didn't clash safely into a tested good folder. You can forget about those.
Now you focus on that folder with the clashing CC, you have to keep halving and testing it. Put the good sides again to one side, take the bad side test and half it.
You will eventually find the file that is causing the trouble even if it takes going down to just 2 files.
Once you know the name of the file open your Sims 2 folder, find and remove it. Find and remove it from your back up as well.
Right click that test sims 2 folder that you did all the testing in and rename it by adding a word onto the end like 'TEST' Then go back to your real folder, right click and remove that word that you added at the start of testing.
The game can have as many sims 2 folders as your PC can take, but making one for testing is always a good idea as is making a full backup.