RS-Prerelease Build 21337 is out to Dev Channel + KB5001618 to .1010

On phase where you had black screen I had this: 0 - 100.

Yes, I see also something new after firs restart: Screen goes black with text "Updating your system (xx%) at bottom of screen before come that new "Updates are underway..." without %.

That happened on all 3 Dev channel PC and one VM.

@Pauli O,

My second desktop same message with spinning dots after first restart, but on second restart just came up with a black screen with only the mouse cursor visible, and just sat there with the black screen..... 

Eventually it still completed the update and came up with 21337.1010.

After 1st restart:

After 2nd restart, no messages at all:

And eventually completed and came up...

 think the wording was changed during the Updating

and the % removed.

It's the Updating Your System that I've never seen before.

Typical MS, the % progress was something useful, so they decided to get rid of it ?

It may only be changed for these servicing CU updates. I noticed that before & then it went back to % for the Build update.

 think the wording was changed during the Updating

and the % removed.

It's the Updating Your System that I've never seen before.

Typical MS, the % progress was something useful, so they decided to get rid of it ?

Yes, I see also something new after firs restart: Screen goes black with text "Updating your system (xx%) at bottom of screen before come that new "Updates are underway..." without %.

That happened on all 3 Dev channel PC and one VM.