"It's Windows" covers sooooo many things
I just ended up with
all the supported Formats of ebook-viewer becoming the shown Icon
I was looking for where they moved the Change Icon (for a file type) fro where it was in <= W7, and I may have done an OK where I usually cancel (when I am just snooping)
I did discover W10
HAS a place to bulk assign formats to a program (don't ask me to find again, fast
)
Re: Magic changes
I suspect some of these were the 'next' in line on the Open with list and 'W' muffed an update and when the update dropped them (instead of replaced/overwrite) when Calibre updated. I have seen a rash of now it is broken,,,now it is working again... in W10