When creating questions for an assessment, you’re given the option to randomize their order of appearance in the assessment. The degree of randomization differs depending on the number you input in the ‘Total random questions’ field.
If you see this error message, it means that your number of questions have exceeded the total random questions count. To put it simply, if you only have 5 questions for the assessment, you can’t have 6 or more total random questions.
Read more on how to randomize questions for your assessment.