Ed: Update: Courtesy of EE member McKnife.
We are aware of a temporary server-side issue causing Windows search to show a blank box. This issue has been resolved for most users and in some cases, you might need to restart your device. We are working diligently to fully resolve the issue and will provide an update once resolved.
This issue was resolved at 12:00 PM PST. If you are still experiencing issues, please restart your device. In rare cases, you may need to manually end the SearchUI.exe or SearchApp.exe process via Task Manager. (To locate these processes, select CTRL + Shift + Esc then select the Details tab.)
Ed: A related Microsoft Help Article that could also prove useful can be viewed here: Fix Problems with Windows Search
Today I received a Windows update to Build 18363.592. After the update, when I used Windows Search, the results just showed a big black square. I often use the search function to find documents and programs on my PC quickly.
At first, I thought something was wrong, perhaps a virus. The best possible solution I could find was a post on the Super User website.
The idea was to update the registry by adding the following DWORD (32-bit) Value:
and also to change the "CortanaConsent=1" value to "CortanaConsent=0" at the same registry path.
Whilst that gave me a quick fix, Cortana had now stopped working.
By chance, I ran Windows Update again and sure enough, there was another update. The second for me today. Now I am on Build 18363.628 upgraded from Build 18363.592. Once the update was complete, I set CortanaConsent back to 1, restarted and all is good.
Hopefully, this will help anybody looking for the same and not try some of the other more complex partial fixes.
Some related questions on Experts Exchange:
Take hold of your future.