If you are using a Mac version of CorelDRAW 2019, then it can be a problem of course to import a Windows version workspace. Maybe it should work right off the bat. But remember, CorelDRAW 2019 for MAC is still an entirely new program. Its built from the ground up to work for MAc. A true native mac version. Yes, we can share file formats and so on between Mac to Windows. But I woudlnt be surpriced if the culprit in your case of the Workspace is that it is Mac version, and your tryeing to import a Windows made workspace.
My advice will therefore be: build a new specifically for your Mac version.