An unrecoverable stack overflow has occurred
From Fs_wiki
Sometimes the whole application exits with the error "an unrecoverable stack overflow has occurred".
This usually happens for a very large survey when it is zoomed out a long way. It was caused by drawing dashed lines that were splined and could be suppressed by ticking the Display | Hide Splines box.
I think it was the one listed under bug 5054725, which now appears fixed in Java version 1.6.0.