** Using WeBWorK **

Basically you don't need to worry about this. It means that that particular problem isn't working -- in this case it almost certainly has a bad link to the java applet that is being called.

This was one of the first problems written used to show the capabilities of java applets and that java applet at The John Hopkins has moved locations over the last 8 years. :-)

You may have to edit your problem to get the correct link:

 	<APPLET CODE="PolarApplet/PolarApplet.class" WIDTH="250" HEIGHT="350"

	CODEBASE="http://www.mat.jhu.edu/~jrm/vander/stable/"> 			<param name=tmin value="0"> 			<param name=tmax value="2*pi">             <param name=showcoords value="yes"> 			<param name=showcoords value="yes"> 			<param name=settrange value="no"> 	</APPLET>

Hope this helps.