I'm trying to perform a simple "Copy with Mates" command in an assembly I'm working on. However, no matter what part I select or what feature I select to form new mates with in "Step 2" of the dialog, it fails out with the message "These mate selections conflict with existing mates."
For one thing, this is a meaningless (and obviously wrong) error message when you're theoretically creating a brand new copy of a part, with no pre-existing mates to constrain it. Beyond the pedantic, it's pretty frustrating to have this functionality completely denied me. Has anybody else run into this, and if so, is there a known workaround? A quick search didn't show any reports of this issue in 2017.
Screenshots are attached.