I tried to use ping.mudfish in order to find suitable nodes for GMS, but this is the result.
Is there anyway to fix this? It was working fine a couple of days ago.
Which IP did you use to test a ping? Did you check that it’s pingable (ICMP ECHO reply allowed)?
I used what google told me when i googled my ip, its my public ip and i dont know how to check if its pingable
It depends your ISP policy then. 
If your ISP allows ICMP echo reply then it works but if not you can’t ping to your public IP.