Samsung 1100DF - Manual (Page 61)

If you see the above message even when the monitor
port is correctly connected to the computer, this means
the operating system does not recognize the USB
monitor. In this case, disconnect and then reconnect the
USB port/cable before running the program. The
operating system should now recognize the USB monitor.
The screen condition has changed
drastically while being adjusted.
Make sure you close the MouScreen program before
changing the vertical frequency or resolution. Do not run
the MouScreen program together with OSD.
Otherwise, the program may not work properly as data
stored in the monitor may be different from those in the
program.
If you close and rerun the program, it will work properly
because it reads the modified data while reloading.