preview of pdf files

[pmshah]

For some reason for the past couple of days it has stopped showing previews of pdf files. Other files can be viewed without a problem including txt, html mkv and what not. It was fully functional and working . Why should it stop suddenly? My OS is Win 10 Pro Version 1903, build 18362.145

[horst.epp]

Looks like you are running an Insider preview as the official version is 18362.116
I run this and SumatraPDF without problems in Everything previewing PDF files.
Do you see the preview in Explorer ?