Hi Kate,
If you drop down the "All Records" option and select some options from the "Posts About" column and let us know if you still encounter an error?
Select, for example, "@Me" or "My Active Accounts" and see if you receive a full list of whats new notifications, obviously these notifications will be specific to your own work. If you don't receive an error it may still be an issue with the security roles so you may need to add read/write/create/share privileges within the Security Roles.
Regards