Hi Natasha,
Could you confirm the following information to help us narrow down the issue?
1. Do you see only the error on Content viewing report? Can you access other reports?
2. Do you have any other site collection on your tenant? If so, could check if the same issue happen on other site collections?
3. Have you turn on the audit settings according to Configure audit settings for a site collection?
4. Have you tried in different browsers?
@Rodrick, since the symptoms you experienced is a little different, could you start a new thread to help us focuses on each case separately?
Best Regards,
Eric Yang