Solution to the "Report Server cannot decrypt the symmetric key used to access sensitive data or encrypted data in the Report Server Database" error

An error occurred while deploying the report:
The Report Server cannot decrypt the symmetric key used to access sensitive data or encrypted data in the database of the Report Server. You must restore the backup key or delete all encrypted content. For more information, see this document.

Solution: delete all symmetric key instances and all encrypted data in the database of the Report Server, and then recreate the encryption key.

Steps:
Run the following command line:
Rskeymgmt-d-I {234a29c8-64d4-4ab5-98fe-0ad282d9d24b}
Rskeymgmt-s-I

{234a29c8-64d4-4ab5-98fe-0ad282d9d24b} is the instance id of your report service installation. The guid value in the rsreportserver. config file.
See http://msdn2.microsoft.com/zh-cn/library/ms162822.aspx for details