LR to PS isn't working

[Bilug]

After updating both LR and PS to current versions (LR10/PS22) everything was working fine. Now, today, for no apparent reason, the Edit in Photoshop option is greyed out.

Any ideas why?

[WobertC]

Check to see if any of these situations apply-

EDIT IN GREYED OUT

Also check the Creative Cloud Desktop App to see if you have multiple versions of Photoshop installed. (More than one may 'confuse' LrC).