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"The scanner is not available while in use by another application or user" message - MF Scan Utility


I have a Canon MF440 Series (specifically, the MF445dw), which uses the Canon MF Scan Utility.  The printer is connected via ethernet cable to a router, which is connected via ethernet cable to my computer.  The computer is an Apple iMac running OS X Catalina.  When scanning from the printer to my iMac, the scan button on the printer opens Canon MF Scan Utility in the background on my iMac as the printer scans to the folder on my computer.  That initial scan works fine.  However, Canon MF Scan Utility remains open in the background after the initial scan, and therefore my next scan (again using the "scan" button on the printer) produces this message:  "The scanner is not available while in use by another application or user."  If I close out the Canon MF Scan Utility (and cancel the scan request on the printer), I am able to start over with a scan request from the printer and everything works fine for the second scan.  However, the problem repeats itself for the third scan, i.e., Canon MF Scan Utiliity remains open in the background following the second scan, so the program blocks the third scan with the same error message as above.  Another interesting element is that when I click "OK" on the error message, Canon MF Scan Utility closes itself and I can proceed with a third scan.  But then it repeats with the fourth scan, etc....


This seems like a silly programming error in Canon MF Scan Utility.  Either the program should quit itself automatically after finishing a scan, or else it should not report a conflict with itself when I go from one scan job to the next at the printer.  It definitely should not throw up an error message that requires me to click "OK" on an error message so that the program closes itself, as this requires me to return to the computer after each scan rather than allow me to scan a series of scan jobs from the printer to the computer.


Is there a solution to this issue?  It's a very surprising problem to arise from a networked printer that is supposed to be good for mutiple users (let alone just one user).  Thank you.

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