Hello
	When I call the method, It returns error like below. 
	<html>\n  <head>\n\t  <title>Grails Runtime Exception</title>\n\t  <style type="text/css">\n\t  \t\t.message {\n\t  \t\t\tborder: 1px solid black;\n\t  \t\t\tpadding: 5px;\n\t  \t\t\tbackground-color:#E9E9E9;\n\t  \t\t}\n\t  \t\t.stack {\n\t  \t\t\tborder: 1px solid black;\n\t  \t\t\tpadding: 5px;\n\t  \t\t\toverflow:auto;\n\t  \t\t\theight: 300px;\n\t  \t\t}\n\t  \t\t.snippet {\n\t  \t\t\tpadding: 5px;\n\t  \t\t\tbackground-color:white;\n\t  \t\t\tborder:1px solid black;\n\t  \t\t\tmargin:3px;\n\t  \t\t\tfont-family:courier;\n\t  \t\t}\n\t  </style>\n  </head>\n\n  <body>\n    <h1>Grails Runtime Exception</h1>\n    <h2>Error Details</h2>\n\n  \t<div class="message">\n\t\t<strong>Error 500:</strong> Executing action [handle] of controller [JaxrsController] in plugin [jaxrs] caused exception: null<br/>\n\t\t<strong>Servlet:</strong> grails<br/>\n\t\t<strong>URI:</strong> /grails/jaxrs.dispatch<br/>\n\t\t\n\t  \t\t<strong>Exception Message:</strong>  <br />\n\t  \t\t<strong>Caused by:</strong>  <br />\n\t  \t\t<strong>Class:</strong> JaxrsController <br />\n\t  \t\t<strong>At Line:</strong> [38] <br />\n\t  \t\t<strong>Code Snippet:</stron"...
	Here is my codes for that.
	App42API::Initialize("XXXXX","XXXX");
	ScoreBoardService *scoreBoardService = App42API::BuildScoreBoardService();
	std::vector<std::string> group;
	group.push_back("AAA");
	group.push_back("BBB");
	scoreBoardService->GetTopRankersByGroup("Level0", group,this,callfuncND_selector(MenuScene::onGameRequestCompleted));
	(the other api method work well)
	thanks