Apple released their latest MAC OS platform called Catalina in October, 2019. In this version, Apple has turned off all 32-bit application support.
For customers who have continued to use the unsupported 32-bit GroupWise 8 MAC client, it will not work once the OS has been upgraded to the Catalina version.
Micro Focus will not be releasing a 64-bit GroupWise MAC client, so the only two remaining options are:
1) Revert back to the prior MAC OS that supports 32-bit applications.
2) Refer to the following guide to enable CalDav, CardDav for native calendar and contact support.