The above error typically occurs because of one of the following:
1) The course is a copy, and the instructor did not open the LDB Dashboard once before students began taking exams.
2) The course is not a copy, but the quiz in question was migrated into the course from an old course, and the instructor did not open the LDB Dashboard once before students began taking that exam.
3) If the D2L Brightspace LMS is being used, the course may have the old legacy LDB settings for the quiz (via the restrictions tab), but the quiz title needs to be updated to include our title amendment (-requires Respondus LockDown Browser).
4) If the D2L Brightspace LMS is being used, the error may be caused by LockDown Browser settings not saving correctly for the quiz. This can be caused by a "null" or an empty value in the D2L "Message" field. This field permits you to have a message presented to students upon test submission. Instructors can see this field by navigating to the course and quiz, then following this click path: Edit Quiz->Submissions Views tab->Default View->View Properties->"Message". The quickest way to resolve the problem is to enter some text (even a blank space using the space key) in the "Message" field and save the quiz again. Then open the LockDown Browser Dashboard again, select the quiz, and save all settings. You can then ask your students to attempt the exam again.
5) Having two Respondus server profiles that point to the same root LMS URL. This can cause problems with D2L Autolaunch of LockDown Browser.
For reasons 1-3 above, opening the LDB Dashboard once for the course (and all others) should resolve these errors. This LTI requirement is always necessary for course copies, and also when a quiz is migrated in from an older course.
Once you open the Dashboard, look for any errors and click the "Fix it" button. You may not see any errors, and this if fine. But the opening of the Dashboard itself will activate the LDB settings for the copy. It is not necessary to re-save each individual quiz's settings. Once you do this, the errors will typically cease for all students who subsequently take their exams.
For reason #5, you should check your Respondus server profiles and ensure that the "URL for root folder of actual D2L system" has a unique D2L URL that is not used by any other server profile.