Jftp 35错误,在joomla的ajax infiniti滚动

Here are lines of code in function

infinitescroll $document = JFactory::getDocument(); 

and

$document->addScriptDeclaration

In function _prepareOutput $document = JFactory::getDocument(); and $document->addScriptDeclaration , that is probably giving jftp 35 error on back admin of joomla regularly, have tried changing the permission of configuration.php file and it havent fixed the issue. On contentprepare function hasnt solved the issue.

what can I possibly do to resolve the issue as it does affect the site when ajax infinity is enabled?