This just happened. Windows 10 Pro and GroupWise 2014 Client 14.2.2 build 128215 on a laptop. I have searched the threads and found answers referencing "mail 32bit" in the control panel, but I cannot seem to find that in Windows 10.
When I attempt to open an address book, all I see available is "LDAP address book". This particular user also uses a desktop computer which does not present the same issue. I assume it has something to do with the user profile/account on the laptop.

Where would I go to fix this issue in Windows 10?