I had a different problem, when using LDAP auth/sync, no NTLM, no chaining. I could log into Share and send an invite, but when invitee clicked on accept link, they would get an error message to the effect that "accept rejected, you have already accepted, of your invitation has been canceled". And in alfresco.log:
09:38:59,839 ERROR [org.jbpm.graph.def.GraphElement] action threw exception: Get enabled is not supported
org.alfresco.error.AlfrescoRuntimeException: Get enabled is not supported
at org.alfresco.repo.security.authentication.DefaultMutableAuthenticationDao.getEnabled(DefaultMutableAuthenticationDao.java:179)
at org.alfresco.repo.web.scripts.invite.AcceptInviteAction.execute(AcceptInviteAction.java:75)
at org.jbpm.graph.def.Action.execute(Action.java:122)
at org.jbpm.graph.def.GraphElement.executeAction(GraphElement.java:264)
at org.jbpm.graph.def.GraphElement.executeActions(GraphElement.java:220)
at org.jbpm.graph.def.GraphElement.fireAndPropagateEvent(GraphElement.java:190)
at org.jbpm.graph.def.GraphElement.fireEvent(GraphElement.java:174)
at org.jbpm.graph.def.Transition.take(Transition.java:138)
(…)
Using this error message, and browsing the source, I found that changing
tomcat/shared/classes/alfresco/extension/ldap-authentication-context.xml:
<bean name="authenticationDao" class="org.alfresco.repo.security.authentication.DefaultMutableAuthenticationDao" >
<property name="allowGetEnabled" value="true" />
<property name="allowDeleteUser">
<value>true</value>
</property>
</bean>
(adding the line <property name="allowGetEnabled" value="true" />)
Fixed my problem, and things look pretty functional now.