We are having a problem with the interface between D2L and Voicethread

We interface VoiceThread with D2L Brightspace. We then set up VoiceThread assignments in D2L and when student log into D2L and go to the assignment, they are able to listen and make comments. What just started happening, is that some people can do the comments in the VoiceThread assignment, while others have to click on another assignment that is set up within the course where they are able to open up the option to comment. Why is that happening for some people and not others. It is happening in both Firefox and Chrome. It happens when we do private browsing or when we clear our browser history including the cache. I am attaching some of the errors we receive.