Steps:
1. Configure keycloak with foreman as per https://www.theforeman.org/2018/06/using-saml-for-single-sign-on-to-foreman-through-keycloak.html
2. Create usergroup in keycloak ex: named "foremanusergroup"
3. Navigate to usergroup- > create new - > add external usergroup and save
4. Click on usegroup created
5. Navigate to tab external usergroup and click on refresh

Result:

External user group foremanusergroup could not be refreshed and also could not able to sync/see users from external usergroup from keycloak in foreman..

and production.log showed
2019-03-12T08:12:23 [I|app|] Started PUT "/external_usergroups/foremanusergroup/refresh" for IP at 2019-03-12 08:12:23 -0400
2019-03-12T08:12:23 [I|app|f33930ed] Processing by ExternalUsergroupsController#refresh as HTML
2019-03-12T08:12:23 [I|app|f33930ed] Parameters: {"authenticity_token"=>"vY7MwjBBMVJ6lAxemIPwy1lM8kwVx4ZqMQrjmHT6e5KgFmJfSil7ae7VYfri7UD/aGCuoMcYLKLNhzwXUlPueA==", "id"=>"foremanusergroup"}
2019-03-12T08:12:23 [I|app|f33930ed] Current user set to admin (admin)
2019-03-12T08:12:23 [E|app|f33930ed] Failed to save:
2019-03-12T08:12:23 [I|app|f33930ed] Redirected to https://foreman.example.com/usergroups/1-foremanusergroup/edit
2019-03-12T08:12:23 [I|app|f33930ed] Completed 302 Found in 13ms (ActiveRecord: 2.8ms)

Expected:

Successfully refreshed external usergroup and also able to sync/see users from external usergroup from keycloak in foreman.