How to reset Cinnamon default themes (they are messed up)? <SOLVED>

[nissash]

So, my Mint Cinnamon default themes are somehow messed up (in "Applications" part).
It started in Mint 20 and doesn't change after updates to 20.3.
When 21 come out I reinstalled Mint (only system, but left /Home untouched).
And the problem is still there.

I tried to download "Adapta" theme and mostly it looks fine (System monitor still looks weird)

I concluded that the problem, maybe, is located in /Home.
At the moment I think the reason is broken default themes files.

Every Light theme looks dark.

Dark Theme


Light Themes



And in System monitor like a mix of light and dark.

[Cosmo.]

When 21 come out I reinstalled Mint (only system, but left /Home untouched).
And the problem is still there.
...
I concluded that the problem, maybe, is located in /Home.
At the moment I think the reason is broken default themes files.

Your conclusion sounds logical, but it does not look, as if the default theme are the culprit. They are not stored in your home and by upgrading they are like fresh installed.

But let us do a test at first:
Open the login window settings and activate the guest account. Reboot and log in as guest. How does it behave there?

[nissash]

Your conclusion sounds logical, but it does not look, as if the default theme are the culprit. They are not stored in your home and by upgrading they are like fresh installed.

But let us do a test at first:
Open the login window settings and activate the guest account. Reboot and log in as guest. How does it behave there?

It is a perfect default themes in the guest account!

[Cosmo.]

For investigating the culprit in your main account:

#1 Delete the hidden folder .cache. Log out and back in and check.

The folder gets automatically recreated.

#2 If this does not help rename the folder .config to .config.renamed. Log out / in.
Very most of your settings will get lost, but you can get them back, by renaming to the original name.

Also here a new folder with default content gets created. If you later want to get back, delete this folder and rename the original folder back. Out / In.

#3 The same as #2 with .local.

[nissash]

For investigating the culprit in your main account:

#1 Delete the hidden folder .cache. Log out and back in and check.

The folder gets automatically recreated.

#2 If this does not help rename the folder .config to .config.renamed. Log out / in.
Very most of your settings will get lost, but you can get them back, by renaming to the original name.

Also here a new folder with default content gets created. If you later want to get back, delete this folder and rename the original folder back. Out / In.

#3 The same as #2 with .local.

Thank You!

#2 fixed everything!
Now Themes are back to normal!

It will take time to restore old settings but it`s fine.
I will move them from the old config to a new folder one by one to not break Themes again