When I edit a link to an external document Calc crashes. Doing: Edit > Links to external files > Modify... a link resulted in a crash. For stack trace and more details see this ABRT generated bug report in the Fedora Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2159079
Please test with a clean profile, Menu/Help/Restart in Safe Mode
Starting with a fresh clean profile resolved the crash. I could now update the link to an external file.
It's not easy to know what parameter on the profile gets the crash.