If a graph you put on your dashboard shows a message like You are not authorized to view this chart, the problem is user permissions for some of the data on the chart.
For example, if you are asking for a chart that contains data on donations and you are not allowed to view donation data -- then you could see this message.
You can allow charts to show the data if you have at least 'VIEW' permission for all of the data on the chart. In the example to the right, the chart has data from: