Cause: All available public servers are servicing requests that require resources locked by a client which is unable to get a public server to release the resources. See the solution below.
Error solution: Increase the limit for the system parameter MAX_SHARED_SERVERS as the system will automaticaly start up new servers to break the deadlock until the number of servers reaches the value specified in MAX_SHARED_SERVERS.
Database version: Oracle 11g Release 2 (11.2)