I recently tried to sign into my Microsoft Account to test out some features which require it(Skydrive, Store, lots of other things). However, when I try to sign in and such I get this error:
"We've run into a problem signing in.... 0x8000FFFF"
Is it just unsupported? How do you test things such as the Skydrive API without having a physical Windows 8 phone?
It's sadly not possible on the public released SDK. It was previous possible in the pre-released versions of the SDK, and during the closed public beta.