I had to upgrade a V5 open source zimbra install for V6.
Before doing it I backed up the /opt/zimbra folder thinking "nothing is going to go wrong".
Long story short, I had to remove the old installation and do a fresh install.
After doing this, I am able to log in via webmail. When I attempt to connect via zimbra desktop with a Zimbra account type I get a "account.INVALID_ATTR_VALUE: zimbraPrefForwardIncludeText must be one of: includeAsAttachment,includeBody,includeBodyWithPre fix,IncludeBodyAndHeadersWithPrefix" error
Nice realy easy to understand error hu?