Q: "Error Occurred while Communicating with the Scanner -9923" (Epson Scanners)

An EPSON WF-7600 multi-function inkjet printer is added to the WiFi network and very soon when I open the scanner, I get the error message -9923. See below:

The "-9923" error appears whenever I try to open the scanner,

1. from Systems Preferences > Printer & Scanner,

, and;

2. from Image Capture,

, and;

3) PDFScanner software encounters the same problem;

4) Another Epson printer on the network has the same problem;

5) HP printer doesn't have the problem.

The "-9923" problem is noticed after an EPSON software window prompting me to change from Image Capture to TWAIN and I am confirmed the change by an Epson Support.

The only software works fine between a Mac and the Epson printers is Epson Scan.

AppleCare Support asked me to attempt

1) uninstall and re-install EPSON printer and scanner software which doesn't work;

2) REINSTALL OS X by Command-R during Restart (a time-consuming job), but it doesn't work either.

Background:

All user accounts on the same MacBook Pro face the same -9923 problem.

Another MacBook Air on WiFi has the same -9923 problem with Image Capture and Open Scanner...

It doesn't fix after applying the application of Epson Printer Software Update from the Mac App Store:

It doesn't fix after applying the EPSONScanPatchForElCapital_100_11.zip (Epson Scan Common Updater);

It doesn't fix after restarting the router (Airport Time Capsule);

It doesn't fix after restarting the DNS server/modem (DLink DSL2900AL);

Any insight?