Had a similar issue.

here is my issue, does a network error and we just upgraded to a new router, game crashes very frequently without our internet even being down

Network error

"problem when communicating whit server"

??

For me, this error occurred happened just after my opponent declared attackers. As far as I can tell, all my other networked applications are working.

I was unable to concede the match either and had to force quit after a few minutes.

I was on turn 3 with my draft deck and this error occured for precisely 5-6 minutes. Just long enough to cost me the match.

This is happening today. Connection is fine, I've restarted, and no other issues with other online applications.

When I start Play and Brawl, the network error message always shows up.
I re-downloaded MTGA, but I have yet this prioblem.

This is apparently due to a new update having been released, but instead of the game saying an update is required it is giving this message.

I am getting this issue right now.

I am having the same problem, constantly. In the middle of a match, it appears as if I’m connected but all of the sudden I can’t play anything, and within a few seconds a “Network Error” pops up. The only way for me to get out of it is open task manager and shut down MTGA and reopen it. There doesn’t seem to be any specific time when it happens, sometimes my turn, sometimes my opponents turn, sometimes late in a best of 3, sometimes as soon as game 1 starts. This started probably about 2 weeks ago and has been happening frequently since. Needless to say, this is extremely frustrating, please do something about this.

two times connection lost... within 5min of play - just got a new Laptop and wuld like to know if new Norton Antivirus culd cause connection Problems?

09:40: got 3 in a row now, culd reconnect once but lost connection only seconds later... No chance to reconnect as Arena doesn´t reackt annymore time ran out ... nothing happend

I just had the same thing happen to me as well, but it would not let me conceded i hard to hard close the entire game in order to exit. It appears to be a common thing that it happens whenever it is the opponents turn, and you are about to win.
My only logical guess could be an exploitation of these under-functioning servers. The opponent may be able to disconnect their internet, causing a network failure for both sides resulting in two losses rather than one. Each player should have their own connection to the server. If the opponent loses connection. It's their loss.

Currently experiencing this error as well. First match of draft fired instantly, then a network error after oppo's first turn. They have 'timed out' without resolving, leaving me with no game actions available aside from conceding.

Edit: restarted program, and apparently I roped behind the scenes for a loss.

Same here. I am going to win my match but I am stuck on that error. If I concede, I lost my draft.

1-1 versus Rakdos Sacrifice, 16min to my clock, 8min to my opponent's clock... I was clearly winning. Would you believe! Surprise, surprise! Just during my attack, my opponent roped and in the end of the rope no answer. I didn't concede because my opponent still have priority (his clock was running out). Then message "Nework Error" and of course no trace of this game in log..... Is it normal? Did my opponent use a bug/trick to cancel the game? When I read messages below, it seems that I'm not alone in this case (opponent's trick).

I had a similar issue. Opponent thought they had won so spammed gg but made a mistake. Then as their timer ran out I got an error message saying Network Communications Error. The game was running perfectly beforehand and now I had to concede and lose progress.

the same on my account. i guess three times

same problem here

Someone just did the same to me except it was right as they realized they were going to lose. They had chose to block one of my units before realizing it would kill theirs and stopped it from doing so. Took some time to count the damage regardless of what they did and realized they lose. Then look at that, all the sudden the game has a network error and I have to concede to get out.

Same issue. I appeared to be connected (connection to MTG Arena seemed to be working and connection to internet was definitely working), and opponents timer ran all the way down, but the game got stuck without using any of their timeouts. About 3-4 minutes later the game finally ended with "Network Error" and no wins or losses tracked on my record.