Hi, if it is a starting member, you will need to manually discover that actor using the plugin command, starting party members are not actually added to the party as they begin in the party, and the encyclopedia is only set up to monitor when party members are added.
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To use the plugin command to add an actor manually, you will create an event, then double click in the Contents section to add an event command. On page 3, at the bottom right, there is the option "Plugin Command" which you will click. In the Plugin Name, choose CGMZ_Encyclopedia, in the Command Name, choose Discover Actor, in the id field, choose the actor you would like to discover in the encyclopedia.