One day, a user is getting errors for a survey when a responder changes their choice on a Choice type question.
I have looked the survey settings, there are a few columns are Choice that only have Yes or No choice.
The cause of the error is that you set the column as unique, so the user cannot select the same value of another column twice. There has another response in this survey which had selected the same value.
So just changed the “Enforce unique values” to No, the problem is solved.