an error occurred while rendering navigation for requested URL/
May 24th, 2015 8:37am
You should look for more details about the error in SP log file.
Also refer to the following posts for more information
http://pacsharepoint.com/2009/11/corrupt-global-navigation-in-sharepoint.html
Free Windows Admin Tool Kit Click here and download it now
May 24th, 2015 2:07pm