missing option to create mock service

Version: SoapUI 5.1.2

I have a new WSDL file for my project so I want to create a new SoapUI project to work with it. When I choose the option to create a new SOAP Project the dialog that pops up does not feature the check box to include a Mock Service; instead it offers just the following:-

1. Project Name

2. Initial WSDL

3. Create Requests

4. Create TestSuite

5. Releative Paths

Before, I've been offered the option to create a Mock Service also.

What am I missing, please?