update installation instructions, fixes #721

INSTALL.md

@@ -20,13 +20,16 @@ oauth.consumer.key.1=CONSUMERKEY
 oauth.consumer.secret.1=CONSUMERSECRET
 ```
 
-3. Edit `/etc/opencast/org.opencastproject.security.lti.LtiLaunchAuthenticationHandler.cfg` and enable:
+3. Edit `/etc/opencast/org.opencastproject.security.lti.LtiLaunchAuthenticationHandler.cfg` and set:
 ```
-lti.create_jpa_user_reference=true
+lti.create_jpa_user_reference=false
+
 lti.custom_role_name=Instructor
 lti.custom_roles=ROLE_STUDIO,ROLE_ADMIN_UI,ROLE_UI_EVENTS_DETAILS_COMMENTS_CREATE,ROLE_UI_EVENTS_DETAILS_COMMENTS_DELETE,ROLE_UI_EVENTS_DETAILS_COMMENTS_EDIT,ROLE_UI_EVENTS_DETAILS_COMMENTS_REPLY,ROLE_UI_EVENTS_DETAILS_COMMENTS_RESOLVE,ROLE_UI_EVENTS_DETAILS_COMMENTS_VIEW,ROLE_UI_EVENTS_DETAILS_MEDIA_VIEW,ROLE_UI_EVENTS_DETAILS_METADATA_EDIT,ROLE_UI_EVENTS_DETAILS_METADATA_VIEW,ROLE_UI_EVENTS_DETAILS_VIEW,ROLE_UI_EVENTS_EDITOR_EDIT,ROLE_UI_EVENTS_EDITOR_VIEW,ROLE_CAPTURE_AGENT,ROLE_API_EVENTS_TRACK_EDIT
 ```
 
+The reference entry in Opencast is neither needed nor wanted, since we are using the Stud.IP user provider. If some actions like ingesting seem to file, when this options is disabled, make sure that the user provider is working correctly. One way to check this, is to call https://opencast.me/info/me.json after opening the videos page in Stud.IP and look for `provider` -> `studip` has to be listed there. 
+
 4. Edit `/etc/opencast/org.opencastproject.plugin.impl.PluginManagerImpl.cfg` and enable: *(Plugin Version >= 3, Opencast >= 13)*
 
 ```