The set of choices must be unique error error appears on single choice, multiple choices and dropdown fields. The actual text of the error is pretty self-explanatory. It appears when choices have the same structure.
Each choice is related to a column in the Submissions table based on an identification number. If choices are identical so is the identification number.
Therefore, our system is unable to separate them and returns the warning message.
The good news is that, these error messages can be solved by you, without having to contact us.
To fix this error go to your fields and ensure that you have different text choices.