This error usually means that you need to select a question that you want to the criteria to be based on. You can choose any multiple choice/numeric question in your survey.
You must choose one (or more) answers to filter on for the question you've selected to build the criteria. If you choose more than one answer, the system will automatically "OR" the multiple options i.e. the criteria will match if any of the selected options are chosen by your respondent.
This error usually means that you need to select a condition i.e a question where the survey should go if the created criteria match or did not not match.
This error is thrown by the system when you do delete a previous question/answer on which your current criteria is based.