pls help : getting an error while uploading OVF package to create vApp Template

I have OVF package to create create vApp Template in  vCloud.

while uploading an OVF package I am getting an error : Fatal error: Call to a member function getFile() on a non-object at this line which is given below.

$files = $fileList->getFile();

The code used is attached below.

I am using this function call to upload an OVF package where i have specified all the three parameters.

$sdkVdc->uploadOVFAsVAppTemplate($vAppTemplateName3, $ovfDescriptorPath3, $diskPaths3);

please help me in resolving this error.