TNS Database Error Messages TNS-04041: CMCTL: Connection Manager already running. Start operation cancelled November 5, 2020 mpbod TNS-04041: CMCTL: Connection Manager already running. Start operation cancelled Cause: There is a Connection Manager already running and listening on the same addresses. Action: No action required. The Connection Manager is already running. 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)