Error: The attempt to connect to the report server failed. Check your connection information and that the report server is a compatible version. The request failed with HTTP status 404: Not Found.
Description: An SSRS related bug, when we try to access a Report Server which is not correctly configured due to wrong or invalid URL then this error shows up.
Solution: The ReportServerUrl property of ServerReport server control should have a valid URL.
<ServerReport ReportPath=”ReportProject1/Report1″ ReportServerUrl=”http://server name/ReportServer” />