MPSSamples, Kajak rebuild issues warnings.

Hi, I am new to MPS. I just installed MPS, and clicked "Open Sample Project" and selected "MPSSamples.2017.2.3\robot_Kaja".

The project opens correctly. From the Project (Logical View) I right click root ("Kajak"), and select "Rebuild Project",

I see the following output:

eg: " Failed to replace dynamic reference 'classifier' with static counterpart: no target; resolveInfo=jetbrains.mps.samples.KajaAndOr.actions.ActionAspectDescriptorImpl. Dynamic reference is left intact. "

The scripts seem to run fine, but I am concerned that I have not done the MPS installation correctly.

Questions:
1. Should the robot_Kaja example build cleanly?
2. How do I go about tracking down the cause of these warnings?

Thanks for your help.