I'm having the same problem as jchamb above. I just installed Splunk 6.5.0 and all the dropdowns are gone and there is no functionality. I have no dashboards, reports metrics, etc. The only drop down is for "Default View". "Dashboards and Views", "Searches and Reports" and "Agent Management" are all gone.
I still see the pre-built panels are still part of the TA under Splunk_TA_ossec/default/data/ui/panels/. You should not lose any dashboard built using those panels unless you have them saved in the default folder.
maybe your dashboard doesnt have permission to the OSSEC app? It works on my end which means could be permission. Either check permission or more those panels to the app that contains the dashboard in question