Playing on PC.
After clicking the Play button, Hearthstone appears to be starting, but a few seconds after that a full screen message appears: “Closed. Hearthstone has been updated! Please download the latest version.”
When I go to Options for HS and select check for updates, I get a green check mark next to the Play button saying my game is up to date. My current version is showing 17.0.2.45932
My connection appears to work normally, it updated the Blizzard Bnet app when I started it today, and also downloaded a 9GB patch for a different game (COD:MW) a few minutes ago just fine.
It seems that either my HS is up to date but it is erroneously detecting it as being out of date, or my HS is out of date and the error is that I somehow can’t get the patch for it.
Edit after several hours:
The 17.2.0 update was offered to me now, and the issue was resolved by that - the game is playable again for me.
Some kind of glitch was preventing that update from being made available to me earlier today, but I can’t figure out why that happened.