Cant use Bootcamp, Mac pro 6,1 thinks it has external

[Cmozley]

I have a 2013 Mac Pro, 2.7Ghz, running Mojave. I would like to use Bootcamp to install Windows 10. My MP is all original, coming with a 500GB Apple SSD. The issue is when I launch Bootcamp Assistant, I get an error message asking me to remove all external drives. I hace done that, but get the same error message. the only thing I have connected to ANY USB bus is my WiFi mouse dongle.

Any suggestions would greatly be appreciated.

Thank you

 

[alin89c]

When I bought my first MBP, I also had problems installing Windows using Boot Camp. To solve my issue, I installed Mac OS X 10.10 Yosemite, installed Windows using Boot Camp, then updated back to Sierra. Now I'm using a software called Parallels Desktop to run Windows on macOS 10.14.6 Mojave (in a virtual machine)...