Hello,
Correct me if I'm wrong but you are running just test suite and trying to create a report for a project. Try either to create a "TestSuite Report" instead a "Project Report" or run whole project, remove -s"Sample Simple TestSuite". Basically if you run a project you can generate only reports for project, test suite only reports for test suite, etc..Report templates that are included in soapUI contains reports from "lower" level item, which means that project report includes test suite reports, test suite report includes test case reports.
Let me know does this helps,
robert