Detecting Devices for Backup

When I try to schedule a back up plan for my passport ultra, the only device that is available after detection is the DROPBOX. Prior to today, the external hard drive was also detected as an option. Has anyone experienced this before and if so how do I fix it to recognize the external hard drive?

Hi,
Windows 10 Anniversary update cause this. I had same problem.
Do a Recovery which will remove the update and return the previous Windows 10 version. MicroSoft is aware of this and I guess working to fix it.

Cliff