I keep a Numbers spreadsheet of domestic finance and for quite some years have been sharing it on iCloud so that Jan can also see what is going on and edit it if necessary (she rarely does). But since 2nd October I've been unable to share this file to iCloud after I edit in numbers and the message contains references about needing a newer Mac. The Mac, dating from late 2014, has been happily updating this and other spreadsheets, and sharing them.
Have Apple Done Something Evil which now excludes my 9-year-old Mac Mini from doing what it has always done? Is anyone else getting a similar problem?