It's in the Windows Insider blog for each release, dev and beta.
I can confirm it works and I'm back to normal.
UPDATE 7:10PM PDT:Recently, Windows Insiders in both the Dev and Beta Channels began reporting that Start and Taskbar were unresponsive and Settings and other areas of the OS wouldn’t load. We quickly discovered an issue with a server-side deployment that went out to Insiders and canceled that deployment. If you were impacted by this issue, you can use the following steps to get back into a working state on your PC.
Step 1:Use CTRL-ALT-DEL and choose to open Task Manager.
Step 2: Choose “More details” at the bottom of Task Manager to expand Task Manager.
Step 3: Go to “File” and choose “Run new task”.
Step 4:Type “cmd” in the “Open” field.
Step 5:Paste the following (everything in bold): reg delete HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\IrisService /f && shutdown -r -t 0
Step 6: Hit enter, and then your PC should reboot. After rebooting, everything should be back to normal.