STM32 products are nothing but problems ... ;(
I had a similar issue, fresh install of SW4STM32 and latest version of CubeMX, and was seeing errors like yours when I imported the project with the instructions on the page you linked.
I was able to get around the issue by making sure the project was not in my workspace directory. Import from another path where CubeMX generated the files, don't copy files into the workspace, and the same code now builds, downloads and debugs with no issues. (STM32F429I-DISCO board.)
Hope this helps!