Broke before even getting into the game

First launch of the PTR.

I tabbed out of it to go back the PTR announcement/notes to review the changes. When I was done, I clicked on the D3 tab on the Start Bar and it borked.

A small white rectangle appeared in the upper left corner of the screen, but the rest of the screen remained as it was (the desktop and web browser were still there). However, I couldn’t interact with the desktop/browser as if something was covering it up.

I tried to tab out again, which would cycle through the open apps on the desktop however, I couldn’t interact with the desktop no matter which app I brought to the foreground.

I had to force shutdown and restart the computer to get my desktop back. I wanted to take screenshots of all of this, but without the ability to open Paint, I couldn’t.

Just had something similar. I was in-game giving someone a 1-70 in Not The Cow Level, charged into a pack of cows and the game just locked up. Used Ctrl+Alt+Del to get the Task Manager active but when that displayed, it was with a small, white rectangle in the top left of screen, Diablo showed as “Not Responding” and the Diablo III mouse pointer was still active. I was unable to interact with the Task Manager, unable to Alt+Tab between Task Manager and Diablo 3, leaving the only option to Ctrl+Alt+Del again and choose the power options to restart PC.

Windows 10 Home, Version 2004, OS Build 19041.1052
Radeon HD6700, 1920x1200 resolution