[Rdo-list] unexpected error has occurred when access and security page

Hi , notebook has 8GB memory, i assign 6144MB to centos 7 in vmware player 12 https://ask.openstack.org/en/question/89430/unexpected-error-has-occurred... i login http://192.168.157.131/dashboard/project/ (http://192.168.157.131/dashboard/proj...) Once logged in to the OpenStack dashboard, click the "Project" tab in the left-side navigation menu, and then click "Access & Security" under the heading "Compute." got error screen Something went wrong! An unexpected error has occurred. Try refreshing the page. If that doesn't help, contact your local administrator. Regards, Martin