in version 8.0.3 to 8.0.4 update the error is:
Shutting down zimbra mail
Backing up the ldap database...done.
Removing existing packages
zimbra-ldap...done
zimbra-logger...done
zimbra-mta...done
zimbra-snmp...done
zimbra-store...done
zimbra-spell...done
zimbra-apache...done
zimbra-core...done
Removing deployed webapp directories
Installing packages
zimbra-core......zimbra-core-8.0.4_GA_5737.RHEL6_64-20130524120036.x86_64.rpm...FAILED
###ERROR###
zimbra-core-8.0.4_GA_5737.RHEL6_64-20130524120036.x86_64.rpm installation failed
Installation cancelled
tnk
Marcelo Rolin
problems upgrade zimbra 8.0.4
problems upgrade zimbra 8.0.4
Have you looked at any of the other threads on this topic and did you try any of the solutions? What errors do you see in the installation log file? Which operating system are you using for this ZCS install?