.DOCX, .PPTx, .TXT not loaded in white board

[Tech Developer]

Hi sir,
     I installed Open Meetings 3.1.1.. I unable to
load .DOCX, .PPTx, .TXT files into white board.
but these files uploaded but deleted message shown in
white board..
     Any Suggetion how i clear this issue..
     And do u provide me above 3.1.1 version OpenMeetings..