In DotA2, why «cannot queue for matchmaking at this time»?

In DotA2, I cannot start a game. After pressing the find match button, I get a message:

Cannot queue for matchmaking at this time.

This happens for both normal games or ranked games.
I could not find anything about a hypothetical penalty, neither in the UI for starting a game nor on my profile.

• Why does it happen?
  It is a penalty? It could have to do with abandoned games.
• Can I see this state anywhere?
• How long can I expect it to last?

My game client is up-to-date.

It's a known bug and it occurs when you leave a finished game too early. To fix this, create custom lobby and leave it or type "disconnect" in console. Then you should be able to queue normally.

This is actually a penalty for various types of misbehavior, such as disconnecting mid-game.