Hi there,
Connection to the postgresql database doesn't work for metasploit after the last updates.
You can check that from msfconsole by typing : db_status which shows : postgresql selected, no connection
As a temporary solution (I hope ;-)), you can, from the msfconsole, type : db_connect -y /opt/metasploit/apps/pro/ui/config/database.yml
This is automatically rebuild the cache and get you connected to the database.
Hope that helps someone out there.