(HELP) Photon PUN has suddenly stopped connecting to the master server when I build the game.

I have been developing my FPS game for quite some time now, but suddenly my friend wanted to play test the game, and it wouldn't connect to the master server when he launched it. The really strange thing is that it will connect in the unity editor, but not when I build it. I've built the game multiple times before this happened so it's quite confusing why this has suddenly happened. Also the build that he was trying to play test on was working ber

I've looked online and tried a number of things, like resetting the RPC's and checking that I have the correct server region (which was fine) and I cannot seem to find any solution that works.

I've put the full error log in a pastebin: https://pastebin.pl/view/a28b5323, but here is the errors that it gives when it cannot connect:
Failed to connect to server after testing each known IP. Error(s):
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:LogError(Object)
Photon.Realtime.LoadBalancingClient:DebugReturn(DebugLevel, String)
ExitGames.Client.Photon.<>c__DisplayClass110_0:<EnqueueDebugReturn>b__0()
System.Net.UnlockConnectionDelegate:Invoke()
ExitGames.Client.Photon.EnetPeer:DispatchIncomingCommands()
ExitGames.Client.Photon.PhotonPeer:DispatchIncomingCommands()
Photon.Pun.PhotonHandler:Dispatch()

Any help would be appreciated :) .