WCF::handleException() Unhandled exception: Could not compile LESS: parse error: unclosed block

#0 /homepages/11/d711562198/htdocs/wcf/lib/system/style/StyleCompiler.class.php(103): wcf\system\style\StyleCompiler->compileStylesheet('/homepages/11/d...', Array, Array, '/* ### blue tem...', Object(wcf\system\Callback))
#1 /homepages/11/d711562198/htdocs/wcf/lib/system/style/StyleHandler.class.php(133): wcf\system\style\StyleCompiler->compile(Object(wcf\data\style\Style))
#2 /homepages/11/d711562198/htdocs/wcf/templates/compiled/0_wcf_1_userException.php(30): wcf\system\style\StyleHandler->getStylesheet()
#3 /homepages/11/d711562198/htdocs/wcf/lib/system/template/TemplateEngine.class.php(323): include('/homepages/11/d...')
#4 /homepages/11/d711562198/htdocs/wcf/lib/system/exception/NamedUserException.class.php(34): wcf\system\template\TemplateEngine->display('userException')
#5 /homepages/11/d711562198/htdocs/wcf/lib/system/WCF.class.php(276): wcf\system\exception\NamedUserException->show()
#6 [internal function]: wcf\system\WCF::handleException(Object(wcf\system\exception\NamedUserException))
#7 {main}