Sorry to hear that you are experiencing this error. The error indicates that the app came across something in your drawing that it was not expecting to see. We have not heard this issue from others, but we are very interested in tracking it down. If you still have one or more of those projects that trigger the error and you are comfortable with sharing your projects with us, please contact me directly (firstname.lastname@example.org), and we can coordinate a way to get those projects from you and debug into them.
Thank you Frank, I just emailed you.