Unable to Add FIDO/U2F Security Key for Azure

[colly72]

I'm trying to add a FIDO/U2F USB security key as a sign-method at https://mysignins.microsoft.com.

 

I've done this before but now I'm getting the attached error:

 

 

Has anyone seen this before?

 

Thanks in advance

[colly72]

This was a bug at MS end. All sorted today.....