Test case gives away solution!

I didn't think the main MATLAB program counted as a toolbox. Oops.

I think James is right: MATLAB itself isn't normally classified as a "Toolbox".   Further, I think there may be another issue too, in that the Test Suite may only be considering Toolboxes from MathWorks, and disregarding third-party Toolboxes (see my Solution 1505802 for more on this), although there is no such restriction in the Problem Statement. On the other hand, that probably wasn't an issue when this problem was created in 2012!  —DIV