using show remote api RESULT=FALSE ERROR_CODE=3891 WARNING=The specified request URI is incorrect.

I am using the following link:

my code works fine for docs and sheets but not ppt?

not sure what is goin on

here is my code(all php variables were received via get)

$fields = array();

$fields["url"] = $apath.'/'.$zohofn;

$fields["apikey"] ="0e9de6e5d3dd2a89d840c4e1960f98e4";

$fields["output"] ="url";

$fields["mode"] ="normaledit";

$fields["filename"] = $zohofn;

$fields["lang"] ="en";

$fields["id"] ="12345678";

$fields["format"] =$ext;

$fields["saveurl"] =$_SESSION['siteid'].'/intranet/filetree_zohosave.php';

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $uurl);

curl_setopt($ch, CURLOPT_POST, 1);

curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);

curl_setopt($ch, CURLOPT_VERBOSE, 1);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

$page = curl_exec($ch);

echo $page;

curl_close($ch);