Please download and run MTADiag and follow the instructions. If MTADiag doesn't launch, please install Visual C++ 2012 runtimes (download and install vcredist_x86.exe) and try again.
Press 'n' when asked.
Post any Pastebin URL MTADiag gives you.
Ok, I understand.
Now I want you to:
1) Disable the wifi and switch to a network cable
2) Play MTA until you get the problem
3) Restart computer
4) Run MTADiag again and show the Pastebin URL MTADiag gives you.
1.3 is unsupported now, and it looks like your startup problem has been fixed in 1.4.
If your friend has a problem with 1.4, tell him to ask here and we will try to find a solution.
I think OP may have jumped to the conclusion that _ is causing the problem. Could be other reasons why the name gta_sa.exe doesn't work with Shadowplay.
No.
Best I can suggest is this:
Settings->Video->Disable Driver Overrides->Check
Settings->Advanced->Fullscreen mode->Standard
This will cause MTA to create and use 'proxy_sa.exe'
Install one of these anti-virus products: https://updatesa.multitheftauto.com/sa/trouble/?tr=no-anti-virus
Also, what is the make/model of your router?
1) Check your computer drivers are up to date. Esp. network related.
2) What is the make/model of your router?
3) Tell your ISP the problem. They might know why it is happening.