Mycloud ex2 power LED goes Red with USB drive attached

Every time I attach a USB drive / pen drive the Power LED on my WDCloud ex2 goes to a steady red and it doesn’t recognise the USB drive through the software. The NAS drives work fine in any case but I can’t access the attached USB drive. When I remove the USB drive , the Power LED goes back to a stable blue. Any help appreciated.

@ranjit2, Please refer to the following article for troubleshooting steps as the external USB Drive Will Not Mount, Not Seen or Detected by a My Cloud: External USB Drive Will Not Mount, Not Seen or Detected by a My Cloud