I've just recently finished upgrading our test SharePoint farm from SQL 2012 CTP3 to RC0. However, now, when I try to create a PowerView report from the PowerPivot Gallery, I get the dreaded "An Unexpected Error has Occurred".
Digging through the logs, I found this: System.Web.HttpException: The file '/_layouts/ReportServer/AdHocReportDesigner.aspx' does not exist
Maybe you can try deleting the existing SSRS service application, make sure that the Power View option goes away from the PowerPivot gallery and try creating a new SSRS service application in Sharepoint.
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