Most Valuable Professional
Group: Forum Members
It looks like you're trying to burn directly to disc there. Out of curiosity, if you choose to create an ISO file instead, does that work? If so, as a workaround you could then right-click that ISO and select "Burn disc image" to build your Rescue Media.
(EDIT: Never mind, I was only checking the second screenshot. Looks like you're trying to make an ISO in the first one, in which case this may be another case of Microsoft having changed/broken something. If so, I guess it's good that these things are at leastbeing caught sooner rather than later for Macrium to investigate. The next Windows 10 release is slated for March.)