Well I updated the launcher, I clicked on 'Installations' tab and clicked my profile, and the profile menu appears so I clicked the version dropdown menu and finally clicked 1.8.9 (which is NOT the same version as I've set before), but 1.14.2 (which is the same version as I've set before) is still there in version dropdown menu.
I had the same problem before, and now everything works fine except the version dropdown menu.
Okay, thanks.