Edit LR Clasic photo in Photoshop

[science scrivener]

Having preprocessed an image in Lightroom, as usual, I clicked on Edit in and the popup window won't allow me to open the image in Photoship.  Both programs are up to date.  What's the fix?

[Rob_Cullen]

What is the exact wording of the error message "won't allow" ?

What is the Version Number of Lightroom? ("Up to date" does not tell us anything!)

What is your Operating system Number?

Where are the Original photo files stored?

Are they on an active connected drive?

Do you use Smart Previews?

Are there any photos in the Library marked as 'Missing' with a [!]?

Are there any Folders in the folder panel marked with a [?] ?

Post screen-clips of what you see by using the 'landscape' icon [Insert Photos] that is above the reply window.

[Just Shoot Me]

Is the original image available or only a Smart Preview?