do you have any firewalls or things of the like that could be cutting you when you join the game?

Thanks for replying. There are no changes in my setup since yesterday, when I was able to complete Act I without too many issues. I am now at beginning Act II, level 24. I have zero network problems with Path of Exile or Diablo III.
Regarding firewall, just default Windows 10, which I tried turning off without any effect.

Just remembering this was happening to me yesterday, something similar at least... rebooted steam and there was an update for steam that seemed to fix the problem, something else maybe to look in to! Best of luck to you getting back to the grind!

Im having the nearly the exact same issue, I was able to play Online without issue for most of Act 1, Now After about one min I get booted to main menu Error: 0 Flashes on the screen.

This is happens on every online charactor even newly created ones, This has been going on for about three days now.

that was exactly my last days struggle...

when u have VPN - disable it.

after that, today i played 2h without discos.

i really hope the devs will allow vpn to their servers. in beta, there was no problems with it.

regards

I was indeed using NordVPN that I had forgotten I had enabled. Now it's working fine - thanks!

Turning off VPN did the trick, Kind of odd it worked for nearly 3 Hours with it on, Must have just been a lucky server.