llaumgui can you share the output of php flarum info
so we can check your Flarum version and the version of this extension
Looking at the source code of the extension, the code for the relationship appears to be there and should be compatible with the latest Flarum. I have not tested the extension recently however.
EDIT: I now notice that in the error message, the latestProfileViews
relationship appears to be queried on a discussion instead of a user. Are you able to share the full backtrace from the log file so we can see which part of the code this originates from?