Odd error. First, double-check that you executed the tutorial instructions exactly. Clicking on the rerun (double-circle) icon per dataset will allow you to review the settings actually used at each step.
If that doesn’t resolve the problem, write back and we can follow up. Note:
Where you are running the tutorial (public server? URL? Other?)
If you are using the tutorial data or your own.
If versions of the tools used differ from any of those in the tutorial.
From an initial guess, this appears to be a problem with the reference annotation or some of the inputs were mixed up, but that is not certain yet.