DAX: RPC error: RPC exception 5 in Ping occurred in session 36

Issue:

BC Proxy account fails to start for the SSRS reports in Enterprise Portal with RPC exception 5

When Enterprise Portal starts for the first time and displays SSRS reports, normally two Business Connectors are started. After a period of time or if the impersonated web user logs out for the SSRS Proxy account you may experience an RPC error 5 access denied and the SSRS reports will no longer display in Enterprise Portal.

Example
Error:

Event Type: Error
Event Source: Dynamics .NET Business Connector 5.0
Event Category: None
Event ID: 180
Date: 10/7/2008
Time: 6:21:04 PM
User: N/A
Computer: AX2009
Description:
Microsoft Dynamics AX Business Connector Session 18.

RPC error: RPC exception 5 in Ping occurred in session 36

Solution:

RPC error 5 can occur if the SSRS Execution account is set in the Reporting Services Configuration Manager. If the account used is the Business Connector proxy account the first startup of the Business Connector will work, but not any subsequent startups unless the IIS application pool if recycled or an IIS reset is done.

SSRS 2005
Remove the SSRS execution account through Reporting Services Configuration Manager

SSRS 2008
Change the SSRS service to start as the Business Connector Proxy account and remove the SSRS execution account through Reporting Services Configuration Manager.
Note: Changing the SSRS account would require a change in the registered SPN’s if you are using Kerberos authentication