3 months later.... Problem still there. still happening all the time to me too. I don't want to play anymore because of it (definately not competitive, but also i dislike other best of 3 games now).

still happening all the time to me too. I don't want to play anymore because of it (definately not competitive, but also i dislike other best of 3 games now (which i prefer over best of 1) and drafting the whole time is costing me a bit too much money.

This is completely UNACCEPTABLE. You CANT play the game if you can't use your sideboard cards.
It's happenning with all BO3 games lately. I am currently UNABLE to play BO3 matches due to this issue.

Playing on tablet. This happens once in 4 or 5games. Please fix this.

Just had the issue happen after losing game 1. Could see my entire library but not my sideboard :(

Dog **** company, just a money grab for fake cards. All this money they get for wild cards and cosmetics yet they can’t fix the core parts of the game like sideboarding maybe these other tcgs will drop apps for their games, can’t be worse than arena

consistently replicable; dc at any time in game and you can no longer sb for any games. Crazy it's been going on for MONTHS.

Any chance small indie company WOTC fixes this? losing ranked games to this is getting old. having to keep mainboarded removal in against creatureless decks is not fun.

Can't sideboard in Bo3 game. Might be due to disconnect during game, as it hasn't happened with the same deck in the last few days. Still super infuriating, as this is such a basic part of the game.

Yeah, this is still happening. Occured during a Traditional Draft for me.

Happened to me during duskmourn sealed event. Very frustrating that a paid event has these type of issues...

UPDATE, RESOLVED MY ISSUE: It was a deck issue for me. That explained why it happened across all my devices. If you export your deck, check the text file for any cards with the "A-" next to the name for the Arena version. I was playing Explorer where Arena cards are not legal, and Knockout Blow looked normal from my sideboard, but according to the export it was the Arena version. This conflict broke my entire sideboard, regardless if Knockout Blow was sided in or not. It creates some kind of validation issue and the game doesn't know what to do, so it doesn't let you sideboard.

Happening almost every match I play in Pioneer. If I reinstall Arena, it will work normal for a match or two, then revert back to being broken. Happens across all my devices. I've tried re-creating my deck, but no change.

Happened to me on android. Can't do any sideboarding.
Version: 2024.41.0.2908.1091998

Just happend to me as I am 2 wins from mythic playing midrange vs control. There is ZERO chance of winning game 2 and 3 without sideboard. Thanks for the free loss. I’m fuming disable best of 3 or fix this insane ********.

Just happened to me in Duskmourne draft. Arena crashed during first game, and then I was unable to sideboard after game 1.

Same issue on PC. I feel this almost always happens when I concede the first round.

Had this issue happen to me as well. Not sure what caused it as previous games it was working fine.

Only difference is that this time my computer crashed during the game and so I logged in on my laptop instead, after which the error occurred.

Same happenned to me during Metagame Challenge earlier today, it's really annoying ans could have caused me to lose the challenge. I have a screen recording on when I managed to get back after short disconnection and not being able to come back

Wotc tooo busy collecting money and being **** stains to fix even the most simple ****, devs theese dyas suck ***, opposite of essential workers, death to all of them

Same happened to me. The sequence was:
1. In game 1 got a short disconnection. Since Arena NEVER manages to reconnect, had to Alt+F4 and launch the game again.
2. Sideboarding after game 1 and after game 2 doesn't let me add cards, can only remove.