Do the errors cause any problem in gameplay? (except showing in the console)
Try Right click MTA > Run as Administrator
Also make sure you have enough space in disk.
The Login window didn't show up. Yeah, I tried running app as admin, disk has enough space.
Then I decided to check if MTA folder was named correctly and it was the problem - I forgot to name main folder as "MTA San Andreas 1.5", instead used custom name. Made a fresh reinstall, everything works fine now.
Thanks anyway and sorry for disturbance.