This can occur when admins are using the Chrome browser, because Flash is disabled by default, in Chrome. To resolve this, try accessing the page with a different browser, or enable Flash for Chrome, using the steps found here:
https://help.salesforce.com/articleView?id=000249731&type=1

If that does not resolve the issue, it's possible that Analytics replication workflows are failing.
You will need to have Support check this for you.