That should automatically be enabled if you have your forum's rss feed enabled: AdminCP --> vBulletin Options --> vBulletin Options --> External Data Provider
enabled it and when i go to the rss icon all i see is this
XML Parsing Error: junk after document element
Location: http://*************/forum/external.php?type=RSS2
Line Number 1, Column 7:<br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><br /><strong>Warning</strong>: Invalid argument supplied for foreach() in <strong>[path]/includes/class_postbit_alt.php(468) : eval()'d code</strong> on line <strong>67</strong><br /><?xml version="1.0" encoding="ISO-8859-1"?>
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You have issues. If you have any rss feed hacks installed - uninstall them and all the files you may have uploaded with the installation - then check again, because you shouldn't get that type of error unless it's a hack conflict of some sort.