Admin menu disappeared after updating to core 1.29.3

The admin bar disappeared after I updated to 1.29.3. I had also updated to the most recent Gin admin theme, so the first thing I tried was switching back to Seven. Same thing.  This was across multiple layouts, including the default admin layout. I could still access the admin pages directly.

It came back after I disabled and then re-enabled the Administration Bar module. Just wanted to mention it in case anyone else is experiencing the same behavior. 

Possibly, clearing the caches again might also have fixed the issue, but too late for me to tell at this point.