You do not have permission to open the scanner application on macOS

“You might get this error when you try to use your scanner from within Image Capture, Preview, or Printers & Scanners preferences.”

Apple has published a supporting document on it website that fixes an error reported by many users while trying to open the scanner from within Image Capture, Preview, or Printers & Scanners preferences. 

When attempting to connect to your scanner and begin a scan, you might get a message that:
-“you do not have permission to open the application “HP Scanner”, contact your computer or network administrator for assistance”
-failed to open a connection to the device (-21345).

Apple suggests to use the following steps to fix this problem:

1. first you have to quit all the opened applications.
2. From the menu bar in the Finder, choose Go > Go to Folder.
3. Type  /Library/Image Capture/Devices , then press Return.
4. In the window that opens, double-click the app named in the error message. It’s the name of your scanner driver. Nothing should happen when you open it.
5. Close the window and open the app you were using to scan. A new scan should proceed normally. If you later choose to scan from a different app and get the same error, repeat these steps.

They promised to fix this issue in a future software update.