We're seeing an Oracle error when adding a question to a question pool or quiz. I was able to reproduce it by adding a Multiple Choice question and filling in necessary fields with one character (question and four answers), selecting a correct answer, and then adding lots of text to the Correct Answer Feedback (over 4000 characters did it for me).
You come back to the main Samigo screen (or see a stacktrace), the question is not saved and the attached stack trace appears in the logs. This only happens on the two feedback fields, the others block you from adding too much text.
I assume this only affects Oracle.