ORA Database Error Messages ORA-01956: invalid command when OS_ROLES are being used June 11, 2015 mpbod ORA-01956: invalid command when OS_ROLES are being used Cause: This command cannot be used when the INIT.ORA parameter OS_ROLES is TRUE. Action: Grant the role to the user in the operating system. Back to previous menu https://support.oracle.com/ http://www.oracle.com/ Share this:Click to email a link to a friend (Opens in new window)Click to print (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Pinterest (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pocket (Opens in new window)