Parallels 13 don't work with Windows 10 Boot Camp External SSD Thunderbolt?

Hello everybody

I want to test parallels, but il's doesn't work...
My configuration : Imac Retina late 2014 (3,5 GHz Intel Core i5) 27 inchs with 24 go of Ram..
I have Windows 10 Boot Camp External SSD Thunderbolt like here :

Everythings works very well and fast ....
BUT
When i launch Parallels 13 I only have that:


and that's all nothing more ....

Can you help me ? I would like to buy parallels for this black friday 2017 but I can't test it....

Have a good day

Tanguy