roundcubemail-core-1.4-209.2.el7.kolab_16.noarch contains the following scriptlet section:
--dir /usr/share/doc/roundcubemail-core-1.4-rc1.27/SQL/ \
--package roundcube || : \
But that directory does not exist, resulting in:
Error 500: Specified database schema directory doesn't exist.
Also, you probably do not want to attempt to redirect stderr as this would hide errors like this.