MIcrosoft blames Mojave, but in reality, Word 2019 is just not truly backward compatible.

The new Office installed routinely, and Word and Excel had no problems with existing files I created under the old version

I've used Word and Excel for years but had to replace older copies after installing Mojave on my Mac

(Files would open, but Word would shut down when I tried to print them.) Learned that existing pdf files are no longer viewable using Word 2019.