I've recently noticed some $NAME.vcxproj files in our repo which have accompanying $NAME.filters files (Some, but not all, have $NAME.vcxproj.filters files too.) These filter files are not updated when new files are added/removed to the project, and Visual Studio doesn't seem to interact with them in any way.
I suspect they were created by an earlier version of Visual Studio, and that a subsequent version upgrade changed the default to .vcxproj.filters and started ignoring the old filter files. But I can't tell when this happened.
Which version of Visual Studio was the last one to generate/interact with $NAME.filters files? Did any version work with both these and the newer .vcxproj.filters files?