Office for MAC 2019 won't open

Issue:   after a volume installation of Office for Mac - Excel or Word will not start.

Environment:

office for mac Downloadversion from a trusted licence shop which includes a  digital licence and a 1.7Gbyte download of the installer.

before I installed the new version, 2 older office version was installed on my iMac and successful removed (also the library files)

Solution:

 open the apple mac store and download from there the later word and excel version, the licence is still valid.