ORA Database Error Messages ORA-26507: null master connection July 7, 2017 mpbod ORA-26507: null master connection Cause: The master connection handle was or became invalid Action: Verify that the master connection is valid 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)