JFBConnect v5.0 uses new "Social Profile" plugins, which are compatible with both JFBConnect and JLinked. The older jfbcprofile plugins no longer work with v5.0. There should have been a notice about this when you installed v5.0 as the old settings from your JFBCProfiles - JomSocial profile plugin would have been migrated to the new settings that the Social Profiles - JomSocial plugin uses. Now, you just need to install that new plugin and enable it.
You can find the new plugin in the 'social profiles' folder of the main zip file you download from this site.
Hope that helps, but if you run into any other issues, just let us know.
Thanks,
Alex