LFS says first with big message "cannot load track" then with small red text "track version is old", when I try to select rockingham, even in offline game

If i reinstall the game, my all setups and game settings disappear?

save ur setups and skins folder and then reinstall.
Game settings like resolution and controller settings u have to configure again.

Did you actually unlock S3? Check in the main screen on the bottom if it says S2 licensed or S3.

OK reinstalled over the old installation and now it works and old setups are still there!

I encountered the same problem when I updated LFS from 0.6H to 0.6M2 test patch. All I did after that was install the 0.6 to 0.6M update and then again 0.6M2 test patch.

Going from 0.6H to 0.6M2 you would not get the various Rockingham files included in the large official patch.

The test patches are just small patches, and it does say 'if you already have 0.6M' next to the download links.