This is an issue we have been tracking for a while now. Please see the KB article on how to get around this error.
After upgrading to System Center 2012 R2 Orchestrator, attempts to start the Orchestration Web Console fails and the following messages will pop up in the browser:
Error Executing the current operation
Error Executing the Current Operation
Starting the Orchestration Web Console fails after upgrade to System Center 2012 R2