Edit in Photoshop CC 2019 not working

I have seen this issue under several other forum threads, but none are explained exactly the same as I'm having.

I hope this the correct forum?

In summary my issue is this:

I'm running a high end Windows 10 based PC

I'm running 3 x M2 drives for my system / working drives

I have archives / backups in an attached Synology NAS (10GB connection)

I'm running the latest Windows updates

I've updated all of my system / device drivers

I'm running the latest updates to LR Classic and PS

When I select any image in Lightroom (any file type from any drive) Lightroom just does nothing.

Photoshop opens, the wait symbol rotates for a few seconds then stops

After 3-4 minutes I get a dialog box that says "The file could not be edited because Adobe Photoshop CC 2019 could not be launched

This happens if Photoshop is already open as well

When I click OK on the dialog box Lightroom then says preparing the file for editing.... and the image opens as a tiff file in Photoshop

This also happens if I click Open as Smart Object in Photoshop

All of my other Edit In links work as normal (Topaz / Nik / DxO)

I have read discussion about reverting to a previous version of ACR resolving this issue on a MAC, but nothing about Windows.

I have tried other suggested fixes such as disabling the Home Screen etc....still the same issue.

This has only started recently and is driving me nuts!  Any help would be appreciated.