Cause : USB memory device operation error comes when an operation command was given during the USB memory device operation.

1. A copy operation (writing) was performed while the PLC function was in the RUN state. 
2. A copy operation was attempted for a password locked project.
3. Check if the USB memory device is operating.
4. Check if the PLC function is in the RUN state.
5. Check if the project data is locked with a password.
6. Perform the operation after the USB memory device operation is completed.
7. Stop the PLC function.
8. Unlock the password of the project data using FR Configurator2. (Refer to the Instruction Manuals of FR Configurator2 and GX Works2.)