PHP Warning: call_user_func_array() amr_debug_time

Did a Google search for: amr_debug_time
Found an indexed SVN plugin page for this plugin in the Google search results: amr ical events lists
http://ww.wp.xz.cn/plugins/amr-ical-events-list/

This is the function in the amr ical events lists plugin that is generating the php error:

function amr_debug_time () {  // track php runtime if debugging
	global $amr_start_time_track,$amr_last_time_track;
	if (isset($_GET['debugtime'])) {
		$amr_start_time_track = microtime();
		$amr_last_time_track = $amr_start_time_track;
		echo '<br />Starting tracking now after plugins loaded '.$amr_start_time_track;
		echo '<br />Note: measuring runtime may affect the runtime too, as will debug messages.  if using ics file, check timing on refresh &refresh';
	}
}

The function does some sort of time debugging and does not look essential to me. So you can just comment out the action that is calling this function with 2 forward slashes as shown below:

The action is located in this plugin file: /amr-ical-events-list/includes/amr-ical-events-list-main.php at Code Line: 2370
//add_action('plugins_loaded', 'amr_debug_time');