Soap error Magento V1.8.1.0

[maartenvdheide]

Good afternoon,

I am working on a new API script based on SOAP for magento.

The script works in a testsite running Magento V1.9.2.2.

When i'm running the script in Magento V1.8.1.0 where it should be running i get the following error:

Call to a member function getId() on a non-object

The code i'm using is:

$soap_update	= $soap->call($session_id, 'catalog_product.update', 
		array($entity, array(
		    	'name' => $name,
		    	'description' => $description,
		    	'url_key' => $name),
		    	'7'
		));

I hope you guys can help.

Thanks in advance.

[maartenvdheide]

I managed to get the script running in a Magento V1.8.1.0 demo shop. 

So this is not a version problem.

Are there any suggestions what the problem can be in the main shop?