I had this problem 3 days ago, seems like a problem caused by Avast & AVG Antivirus, because i had AVG and on the moment that i uninstalled it, MTA run as is normal.
Two friends have the same problem and they use Avast
Since today i can't play MTA because when i try to play the client starts to freeze, and do a loss of fps among 60-25.
I've tried to reinstall the client and install the nightly client 20180824 but it keeps unworking.
If it's necessary here is the MTADiag log.
https://pastebin.mtasa.com/621853575
PD (Sorry for my bad english, i'm from Mexico, thank everyone)