When you have more than one eDirectory instance, the second instance and subsequent instances try to listen at the default 524 port instead of the NCP port on the loopback address.
To work around this issue, set the n4u.server.tcp-port parameter of the second instance to the port that it is supposed to listen on. The n4u.server.tcp-port parameter is located in the nds.conf file.
IMPORTANT:All eDirectory instances must be up before upgrading to eDirectory 8.8 SP8.