Use the following tools, referenced in the Onfolio Knowledge Base articles, to fix any problems you might be having.
SimpleActivation An application that will connect to the Onfolio activation server without the use of a web-service based connection.
whidbey_config A set of configuration files that can be used to ensure that Onfolio uses the correct version of the .NET Framework.
CPUPatch A patch for a known bug that can, in extremely rare cases, cause the CPU of the computer it is installed on to spike.