Cannot generate reports from SQL Management Data Warehouse

I'm running SQL Server 2008 R2 and have installed the MDW on one server and have a Data Collector collecting and uploading the server activity, query results, and Disk activity data to the MDW. When I select any of the reports from the MDW with Data Collection > Reports > Management Data Warehouse I receive the error: > *Exception has been thrown by the target of an invocation - > Object reference not set to an instance of an object.* This occurs for all 3 reports and after I've waiting some time and data has been uploaded from the data collector. I do not have SSRS running, but read that isn't necessary. Any suggestions?