One of our Microsoft CRM 4.0 customers called me urgently asking for help to resolve a companywide Microsoft CRM 4.0 login issue. None of their users were able to login to Microsoft CRM including the CRM Administrator. They all received the "Invalid Action – The selected action was not valid" error message when trying to login to Microsoft CRM.
I had encountered this issue before – so I quickly verified it by trying to login to Microsoft CRM from their CRM Server (same error!) and then reviewed the Event Log. There was an event error in the Application error records view: "Current active key (KeyType : CrmWRPCTokenKey) is expired. This can indicate that a key is not being regenerated properly…"
The resolution for this is to check the state of the "Microsoft CRM Asynchronous Processing Service" on the CRM server and ensure that it is "Started". Issue solved – everyone can login to Microsoft CRM again.
Somehow the service was stopped. This may indicate another issue or it may not – I’d suggested to the CRM Administrator to monitor this and keep me posted if it happens again.