CorelDraw2017 crashes opening .cdr files created in CorelDraw6

I've just upgraded to CD2017 from CD6 (bought in 1995). Most of the .cdr files show an error dialog when I try to open: "invalid fill ID". When I click on "ignore", CD2017 crashes, invites me to tell Microsoft.

If I open the same file in CD6, copy the content & try to paste into a new doc in CD2017, it crashes just the same.

Would love to hear of any workaround to save my extensive set of files.