Tumblr API createPost method error in laravel

Hi I am using Tumblr PHP client to make post into my Tumblr blog . I have created an app using laravel to post my content into Tumblr . I'm following this => http://ift.tt/13N9duT

but when i run this code

$client->createPost($blogName, $data);

it returns and error Error message :

FatalErrorException in RequestHandler.php line 86:
Cannot unset string offsets 

How can i solve this problem ? Thanks

via Chebli Mohamed