Before releasing a patch, see if all the powers work.

CrookedKnight

I'm not talking about checking every possible wacky edge case. Have some QA people, whom D3 presumably employs somewhere, play the 38-ish matches needed to cover every recruitable character. Each match should be brief -- use debug access to start with 30 AP in all covers, fire every power once, let the fight go to the second turn to ensure passive powers are doing their thing, futz around until countdowns resolve if needed, then retreat and move on to the next set of characters.

This is not in-depth play testing by any means, but it would have caught the current invisibility bug, the Whales Whales Whales! bug, the Hot Dog Stand bug, the old Shadow Step/We Are Iron Legion bugs, etc. Even if you don't have leeway to hold the patch until it, y'know, works, you could at least get out ahead of the problem with patch notes and a timeline for fixes rather than letting the players discover errors on their own.

This may sound like sarcasm, but it's not. Optimism, maybe. I'd rather believe Demiurge/D3 doesn't follow basic testing procedures than that they are user-hostile enough to put out software with known bugs and not take any effort to flag or route around them.