Pro: I can't delete the files inside...

I need to delete all the contents of my MyPassport W Pro. I can’t do it from the Finder and not even via http: //mypassport.local/UI/ Anyone have any idea what happened?

If you want to delete all the contents in you drive, just plug the drive direct to your computer using the USB cable. From the computer side format the drive. Everything files/folder will be lost.

Does doing that also remove all of the Plex/Twonky files and folders required to run those programs?

If so, then I would suggest simply using the “system and disk” option in the Restore Factory Settings tab of the (https://mypassport.local/UI/) if possible.

System and disk option would delete all delete all contents on the disk.