Problem importing the data file with CAD import module

Hello every one,

when i try to import the scalar expressions for open_pipe model (under acoustic module) from cad data file, i get the following errors

Erro : 3015
Unrecognised file type.


Exception:
com.femlab.util.FlException: Unrecognized file type.
Messages:
Unrecognized file type.

Stack trace:
at com.femlab.geom.GeomImportRunnable.a(Unknown Source)
at com.femlab.geom.GeomImportRunnable.usesImportTol(Unknown Source)
at com.femlab.commands.CadImportCmd.evalOnServer(Unknown Source)
at com.femlab.commands.FlCommand.runServerCode(Unknown Source)
at com.femlab.server.ServerProxy.eval(Unknown Source)
at com.femlab.commands.FlCommand.a(Unknown Source)
at com.femlab.commands.FlCommand.eval(Unknown Source)
at com.femlab.commands.a.a(Unknown Source)
at com.femlab.gui.dialogs.ImportCADAccessory.a(Unknown Source)
at com.femlab.gui.dialogs.bv.b(Unknown Source)
at com.femlab.gui.dialogs.bj.a(Unknown Source)
at com.femlab.gui.FlProgressThread.run(Unknown Source)
at com.femlab.util.i.run(Unknown Source)
at com.femlab.util.aa.run(Unknown Source)


I am just the beginner in comsol environment..

Please help me to solve this problem...