Getting error message on form submission and ajax submission.

Please have a look on the below text. These are the error message that I am getting when submit a form or ajax request. Please help me to clear this issue.

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<b>Deprecated</b>:  Automatically populating $HTTP_RAW_POST_DATA is deprecated and will be removed in a future version. To avoid this warning set 'always_populate_raw_post_data' to '-1' in php.ini and use the php://input stream instead. in <b>Unknown</b> on line <b>0</b><br />
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<b>Warning</b>:  Cannot modify header information - headers already sent in <b>Unknown</b> on line <b>0</b><br />
{"id":"0","js":false,"text":""}