When you search in Outlook the following error occurs:
“Outlook cannot perform the search.”
Note: This only occurs if Outlook is on Windows Server 2016 Terminal Server or Windows Server 2016 Remote Desktop Server.
This issue may occur after installing the following Windows Update:
KB 4467684: November 27, 2018—KB4467684 (OS Build 14393.2639)
Microsoft is aware of and investigating the issue.
As a workaround, you can open your Windows command prompt, type sfc /scannow, press Enter and restart Outlook to alleviate the symptoms.