When a player is disconnected during gameplay, and often leads to being dropped from their event.

When lag causes a misclick or skipped action. The user isn't disconnected from the client though.

When the User Experience or User Interface is involved in an issue. Generally not a technical bug, but where the client could be improved to help reduce confusion.

I was playing and Magic Online suddenly crashed and I pressed the buttons in an attempt to get back. It turns out that the game recorded what I pressed and still crashed. When I came back to the game, after reopening Magic Online, he understood that I "pressed" the buttons even with him frozen and that cost me the game.

Ingame crash for both players, MTGA start unpossible for both... (iminnent crash)

Raka Santuary does not recognize when you control a blue permanent and a white permanent.

Mana freezes in the middle of my screen an my creatures freeze on the side so I can't tell if I can use them or not it's also the same for my opponents creatures as, I'm unsure what category this goes in for issues though

Confounding conundrum recognizes the first land entering the battlefield as a result of field of ruin as if it was the second land, forcing you to return 1 land to your hand.

I cast the new spell shatterskull pass and it automatically set X = 1.

I cast a manamorphose for double red, cast the second pay it with the 2 manas of the first manamorphose and automatically add other 2 red mana without the possibility to choose the color (I would add red and black)

Sheltering Ancient was played on my opps side; I had a creature in play. The first cumulative update put a counter on my creature, but all subsequent turns saw the effect not take place.

Did not place counters on eligible creatures on my side of the battlefield after the first cumulative upkeep trigger was performed.

Ceta Sanctuary does not recognize second state

quando estava faltando no meu relógio 14:20 o oponente usou a carta Cast Down que não pode ser usada.

I activated a Volrath's Shapeshifter and went to click the Hellkite Overlord in my hand. The game stalled, and rebuilt twice before stopping at Turn 1 with our original hands. At that point, the game forced us to yield about five turns each, including discarding to hand size.

Massive lag due to Scute Swarm, couldn't end game due to timer went down

When Volrath's Shapeshifter takes on a new shape due to the top card in the graveyard being a creature card, it becomes invisible and cannot be used to attack, block or otherwise interact with.

As can be see in the attached chatlog, the etb ability of the creature in the graveyard still triggered (that creatures being Vendilion Clique).