Looks like there is somewhat of a rough road for those upgrading from GroupWise 7. One error I saw with no absolute resolution posted online gave me a bit of fun. Error being the following:
procedure entry point ??OCLdapConnect@@QAE@PADHOH@Z could not be located
in the dynamic link library GWLD0132.dll
Don’t try a reinstall by itself. It will just kill time. What will solve this is a free tool that I’m surprised I have not heard about in the past called CleanIt (Fill out your info and it will show a page with a quick download link.) Remove all GroupWise programs from Add/Remove Programs. Run this program and clear out old files. Then try your GroupWise 8 install one last time.
For detailed information on why this is happening, check out this article from Novell which discusses in depth about why this error happens.