You don't give any detail, like what version of Processing you use, what your code looks like (big or not?), when do you have this error (when hitting run?), and so on.

The trace suggests you get this error when the PDE tries to report an exception in the running of your code but fails because it scrolls to display the faulty line, the syntax highlighter kicks in to highlight the new portion but fails on a token, for an unknown reason.

That's not a programming question (you don't show any code), so I moved the topic.

sorry for that's.