If you have installed Alfresco manually or upgraded from a previous version of Alfresco, you might not have installed the Alfresco Office Services AMP file. If that is the case, you will receive an error message "The address is not valid" when you try to connect and authenticate with the address: http://server:port/alfresco/aos. You will also see the following error message in the server log:
Blocked a directory listing request from MS-Office. This indicates a broken MS-Office
deployment. Please check that the ROOT and the _vti_bin webapps are deployed properly and
reachable from the outside!
To fix this problem, ensure that you have installed the Alfresco Office Services AMP file, and deployed the _vti_bin.war file that is required for AOS to work correctly.
See Install Alfresco Office Services for more.