Well done Steinberg, great news. Although i think Quicktime is also compatible now.
Steve.
Well that’s good news. I installed the latest Quicktime without issue yesterday. I bet there will be a lot of O/S downloads over the next few days! hopefully not too many issues…
I just installed Quicktime on Windows 10 Pro x64 successfully.
My Quicktime 7.7.8 installed in Win8 works perfect in Cubase on Windows 10. 
Finally I can use Windows 10. I like the look of it, and it seems fast.
It’s been working fine for months. The 7.7.8 Quicktime version has been out and working on Win10 for months also.
Party time. Everything is now Win10 Compatible. I got the new UR44 driver last week and so far had no problems.
Good work Steinberg