I have just downloaded the fresh copy of phppowerpoint and added the following line of code 'phppowerpoint' => MODPATH.'phppowerpoint', and now my page got blank and I got the following error:

The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must to be declared in the document or in the transfer protocol.

Any thoughts? Thanks.