Dashboard Error: "The source report has a report type that is inaccessible to the dashboard's Running User"?
In some cases you may see this Dashboard component error: "The source report has a report type that is inaccessible to the Dashboard's Running User."
What this means is that the running user does not have correct permissions to view the object that the underlying dashboard report pertains to.
For example, on the Adoption Dashboards that you can download from the AppExchange, some of the dashboard components (and reports) are about user logins. If the running user does not have the proper permissions to see user-related info, you will see this error on the dashboard.
The solution in this case would be to modify the profile for the running user to provide either the "Manage Users" or "View Setup and Configuration" permission. The "View Setup and Configuration" option allows a user to view all setup info, including user records.