Connected remotely to the user using anydesk to check the application on their side and to check the exact cause of the process when the error is encountered, as per checking, the cause is at the middle of the printing, there is an error which is the connection is lost (though their connection is OK) thus return an error when extracting data from JDA, but the first UPC is printed. Modified and changed from mmpydlib into mmwmslib, this is the library where the data is extracted, and tested it on the user side, as per testing, the error is still encountered, the checking and testing will continue tomorrow.