OpenLogClass and OpenLogFunctions are not relevant for this. They're a Java class for use in Java agents and a LotusScript library.
It's not finding the OSGi plugin (or extension library) in the Update Site database. As for the Extension Library, it's worth checking the steps in Chapter 2 of XPages Extension Library book.
tell http osgi diag com.paulwithers.openLog/ tell http osgi ss com.paulwithers.openLog will tell whether the library is installed or there are any dependencies missing. There should not be any.
The main thing to check is that the OSGI_HTTP_DYNAMIC_BUNDLES notes.ini setting has been added and maps to the relevant update site database. If the notes.ini variable is set, when HTTP starts the console will have the message “NSF Based plugins are being installed in the OSGi runtime.”