add SSRS pool to SharePoint - few issues

Question

i know this is gonna be a Little akward because the Image i am gonna post is in German, but essentialy what i am trying to do, is create a Service Pool for Reporting Services,

now it is Very important that i am able to check the last Checkbox so my PowerPivot is gonna work, but i don't know what it is that's making it impossible for me to do so, anybody have any Ideas ?

NOTE: the message sais: There are no Webaplications associated with this SQL Server Reporting Services-Service Application available

Your Help is as always well Appreciated!

Answer 1

Fixed it, by removing the existing Association beetween the SSRS Service with the Web App, apparently you can only associate one SSRS Service per Time