My opponent was trying to resolve hundred's of cantrips. His time out's ran down, as they should, but then the game never passed turn to me. My opponent just kept resolving the cantrips. Then my time outs ran down, while it was still my opponent's turn. Then I got the inactivity warning. I tried to take some kind of action, but it wasn't my turn, there was nothing I could do. When everything finally resolved and turn passed to me, I was immediately given the loss for inactivity. I had my win condition on the board. I had a 100% chance of winning with my Angel of Destiny on my next turn. But I never got the chance. I thought the turn timer was fixed when people were popping hundreds of insect tokens. What happened?

A similar thing happened to me, lost my timeout extensions, and almost timed out. Multiple turns of mine were skipped, and one of the basic lands I played on the turn that got skipped otherwise was not able to be used later in the game.

I wrote a lengthy e-mail to customer support about the root cause of this issue, and was told to come here, where bug reports and suggestions go to die. Here's part of that e-mail:

There must be a technical issue causing this lopsidedness in time usage, because I did NOT spend almost 15 more minutes than my opponent making decisions while having priority.

Ever since I started using Hughesnet satellite internet, I have noticed this timer issue in Arena. You see, Hughesnet typically has 1000-2000 ms latency on every request. This means that EVERY SINGLE THING that happens in Arena takes off an additional 1-2 seconds from my time, even though I'm not stalling at all. You can imagine how that adds up in a long best-of-3 matchup by game 3.

Solution: Don't penalize the player for the time it takes for the round trip it takes to do every single thing that the game does. Tap a land? Cast a spell? Activate an ability? Resolve individual stack effects? Declare attackers? Declare blockers? Damage? You get the point. EVERYTHING adds 1-2 seconds due to technical reasons beyond the player's control. The time waiting for network responses should not count towards a player's time.

Happend twice for me tonight so far, both on ranked games. Their timer ran out on a 140+ stack and it went in to auto-stack-resolving mode, during that mode my timer started ticking, finaly giving me a warning about my inactivity (still during the opponents turn, with the stack still resolving) and as soon as it went to my turn it gave me the loss instantly as I had no time left to even react.

Happened to me too, cost me a game. Opponent kept triggering this bug for several turns.

Please allow us to autoresolve the stack or turn off animations to disable this exploit.

Happened to me with my opponent using scute scorn and migratory greathorn. Lost all my timeouts waiting for over 200 copies to be placed and then lost the next turn due to no timeouts left.

My timer kept running out during the opponent's turn because they had too many things on the stack, even tho I had resolve all checked and pass turn.

This also just happened to me. then as he declared an attack. I had more then enough creatures to block but did not have enough time to actually assign all my blockers. The damage was lethal only because i didnt receive adequate time to assign my blockers because he used up all of MY time saves putting counters on his creatures from his cards trigger resolving.

Happening to me right now. Opponent resolving 250+ Scute Swarm triggers plus an Ogre Battledriver trigger for each new creature token. I had a time extension run out before the "Resolve All" appeared for me to click (which I did). It's been about half an hour, and still more than 200 Scute Swarm triggers remain. All accrued time extensions have been used up, even though I am not taking any actions as the stack is resolving.

This happened to me too. I managed to get a video of it happening. Luckily for me it stopped at the end of the video, otherwise I would have lost for no reason (if anyone wants to know what happened next, my opponent's Risen Reef/Zendikar's Roil combination made him draw all the cards in his library except the 3 last ones, then he used Jace, Wielder of Mysteries to win).

This occurred with me when someone spawned 600 Scute Swarms. Attached my log to help.

Really novel idea here. You guys have obviously never thought of it.

SORT YOUR TURN TIMER OUT SO IT DOESN'T RUN DOWN WHILE YOU CAN'T DO ANYTHING

If my opponent puts 300 triggers on the stack and I select auto resolve, my turn timer should never come into the equation, let alone burn through 3 or 4 of them while his effects are resolving.

Steps to reproduce:
Play your own game with an eye towards QC sometime?
For this particular incident, have 2 Impassioned Orators out, 1 Gideon's Company, 1 Krenko, Mob Boss, and a couple of hundred goblin tokens.
Activate Krenko, and watch your poorly coded software burn through everyone's time outs.