This has happened to me in mobile just now.

Plzz fix

Can't sideboard at all im most bo3 games. It's been ongoing at happens on two different PCs, both windows.

Same issue on mac

Having this issue as well

Other notes - I play on multiple screens and was doing something on other screen when g1 ended
Restarting client or changing the view does not resolve this

Still an issue on PC, BO3 is unplayable

Cant sidebord on Windows

I also cannot sideboard. Android and it always happens after my game crashes and I need to re-enter. Crashes during sideboards are getting very common as well.

Cannot sideboard on iOS

No sideboard when
1) I am disconnected
2) I have companion .In this case You must first remove the companion and then insert the cards

Please make the sideboard work. It breaks BO3

Couldn't sideboard in ranked after I got disconnected :(

This game sucks after the update. Can’t sideboard if you get disconnected which happens more and more.

JFC WotC it has been a month and this is still an issue. Not to mention some other fun and maybe related issues where both players are constantly being disconnected from the server and when reconnecting the client often just straight up freezes up and crashes. Every time I see the 'this weeks Arena update' post I always wonder if *any* of these critical issues will be fixed but they never are. Can you please squash some bugs?

Having same issue on PC, Explorer bo3 with companion. Cannot sideboard

Reporting the same problem on PC Windows 10. Fresh Install.

Experienced in Timeless Best of 3 and Explorer Best of 3. Both decks had a companion.

same on mac plz fix asap

Same problem, cannot sideboard after the update, was able to for the first 3 games, but now it's not working. If I uninstall and reinstall the client, then it works for a match, then the 2nd match the sideboard will NOT allow me to bring in any cards.

Please fix the bug.
MTG arena tends to harm the Magic: the Gathering brand reputation.

Can’t sideboard in timeless bo3 after game1 happened last season to