Please, if you find any bur or just weird thing, post it here.

Direct Installation of Mods:
0) Make sure that you are not subscribed to the mod in Steam workshop.
1) You need to have .rar archive with a mod folder and .mod file for it.
2) Go to Documents\Paradox Interactive\Name Of a Game\mod.
3) Extract folder with the mod and .mod file there.
4) Start the Game and select the mod in launcher.
5) If something goes from go to point 5 of "If you have a subscription to mod on Steam and something goes wrong".

When you want to use Steam Workshop version, after using Direct one:
1) Manually delete a folder and a .mod file from Documents\Paradox Interactive\Name Of a Game\mod.
2) Subscribe to the mod in Steam Workshop.

If you have a subscription to mod on Steam and something goes wrong:
0) If you have never done it with New Launcher - delete mod folder in Documents\Paradox Interactive\Name Of a Game\mod.
1) Make sure that you have downloaded the files from Steam Workshop or from Paradox Forums.
2) Go to Documents\Paradox Interactive\Name Of a Game\mod.
3) Find ugc_number.mod of Mod that is not working. Remember the Number.
4) Go to Steam\SteamApps\workshop\content(id of the game)\Number.
5) Check, that folder is NOT empty. And find virsion.txt.
6) In version.txt check that you are using the Last version of Mod.
7) If version is last and folder is not empty - Contact Us.
8) Else - unsubscribe from mod in Steam Workshop.
9) Manually delete the folder with Number in content folder and ugc_number.mod from Documents.
10) Restart Steam and Launcher.
11) Subscribe to mod again.
12) Check version.txt Most recent Version you can found via Steam (in Updates), via Paradox Forums or Discord (in Announcements).