I have a CFD model that is about two stroke engine using Ansys12.0 FLUENT, the model employs the multiphase model due to mixtion of air and gasoline vapor in cylinder, there are interfaces between inlet and cylinder, and the fuel injection mechanism uses dynamic mesh event to "create sliding interface/delete sliding interface", but the sumulation result display

Execute Event: in-open (defined at: 200.00, current angle: 200.00)
Error: eval: unbound variable
Error Object: motion-bc

But, there is no problem in Fluent 6.3.26 version