SAP Netweaver Gateway has been deactivated

Hello

I've tried to create GW Data Model and GW Consumption Model using this guide.

I did everything written there but at the end when i tried to look at this XML i recieved this in my browser:

<error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">

</error>

Can you tell me please, what could be the reason for that?

Thanks in advance!