ok so I tried both methods and neither of them worked(guess the problem has something to do Chrome) but i installed Opera Browser and added the Savefrom.Net extension to it and it works like a charm. 

so I will be using Opera when i want to download from VK.

thanks a lot for your help and this great extension.

i dont know what happened since yesterday cause i didnt change any of Tampermonkey's settings and today i just tried this thing that you recommended to do which was changing the Download Mode to browser api and it didnt work so i changed it back to default settings