Open Radar

 
This is new in macOS Big Sur 11.6.6.  

ISSUE: If a user opens a file from another app (i.e.: opening a PDF from Mail), and that file's default app is still open, the following error message appears, and the file is not opened:
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Error message: The file “B5EX35-text document.pdf” couldn’t be opened because you don’t have permission to view it.  To view or change permissions, select the item in the Finder and choose File > Get Info.
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STARTED OCCURRING: immediately after update to Big Sur 11.6.6.

REPRODUCIBILITY: 100%

SCENARIO: 
This can occur most commonly when opening email attachments from Outlook or Mail, or when opening PDFs from your preferred web browser and Acrobat or Preview is the preferred handler.  In theory this can happen with any file type.  

WORKAROUND:
Quit the default app that would have been used to open the file.  The User must do this EVERY TIME a file is opened in order to open any more documents.

STEPS TO REPRODUCE:
1. If Preview is open, make sure it is quit / not running.
2. Open or create any text document.
3. Click file > print…
4. Click the “PDF” drop-down and choose “Save…”
5. Save the file anywhere, e.g.: Desktop.
6. Locate the saved PDF.
7. Open Safari.  
8. Open the PDF in Safari.  Example: drag-and-drop the PDF into any Safari window, or onto its Dock icon.
9. Move the mouse near the bottom of the window until the “overlay” appears with four buttons: (-) (+) [Preview] [Download].
10. Click the button representing Preview.  The document should open in Preview now.
11. Close the document but leave Preview open.  The Dock icon may disappear.
12. Click the "Preview" button in Safari again.
13. User is now presented with the error message about permissions.