PLS Database Error Messages PLS-00256: string is not a valid external library February 24, 2021 mpbod PLS-00256: string is not a valid external library Cause: The supplied external library name in the external clause is not a valid alias library. Action: Provide the name of a valid alias library that has been previously declared. 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)