Hello again, @heliboy.
I appreciate you getting back to me and for providing a screenshot. I'm here to help make sure this is taken care of.
This may cause by damage QuickBooks functions which prevent the system from recognizing the scanner. Uninstalling and reinstalling the program can help fix the issue. This process is also called a Clean Install.
1. Close/Exit QB and click the Finder menu on the desktop, then Go.
2. Select Applications, then drag the QB icon to the Trash.
After that, remove QuickBooks PLIST files to revert all preferences to its default settings. Here's how:
1. Go back to the Finder menu, then Go.
2. Hold the Option key, then select Library.
3. Open the Preferences folder, then find the PLIST files with QB and your version in the name, then drag them to the Trash.
4. Empty the Trash.
Restart your computer, then reinstall QBDT. For the detailed steps, check out this article for further guidance: Install and set up QuickBooks Mac Desktop.
For additional information, I'm also including this article that tackles reinstalling QuickBooks for Mac using clean install.
That should get you back in the right track. Let me know how it goes after giving this a try. I'm only a few clicks away if you need anything else. Enjoy the rest of the day.