Hi, When the computer goes to sleep, the driver for the dongle also goes to sleep (probably the dongle's light is off), then the program is popping up this error message because it can't find the dongle. If you will not be at the computer for a certain period of time, it would be reasonable to exit the program and leave the computer as it is. Regarding the computer going into sleep mode; How to control the USB can be regulated in the Control Panel / Power Options section.
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