Understanding Scorable Units

Hi All - I am actually licensed for Saba Publisher 9.0, which I understand is a re-badged Lectora. I am working for a big corp and there is no internal support for developers. I have been provided the license and am creating some of the first titles that we have produced. I am not a completely new user, I have previously created a number of self-running tutorials and am fairly familiar with the application. I have printed out the documentation and read it but there are some things I just don't get and also don't know where to look.

The tutorial I have created comprises 15 pages and then a single page Test, with 5 questions on one page which are a combination of multiple choice, fill in the blank, and true/false. Each question is worth 1 point. The Results tab in the Test Properties has Grade the Test checked and Lowest Passing Score set to 75% . I have added a Submit Button to the Test page which is set to Action: Submit/Process Test/Survey. The Target is Assessment, which is the test name, and the only choice for this field.

If I set the Content tab of the Title to AICC/SCORM, I have noticed it automatically creates an Assignable Unit at the top of the content tree.

Now I would have thought that by doing this, I would have created a 'scorable test'. But the error report says that the Assignable Unit is missing a scored Test or Modify Variable action.

Any tips or pointers would be most appreciated