When i Import the items i got some DMF errors finally i got the solution

Error:

Could not load file or assembly 'Microsoft.Dynamics.AX.Framework.Tools.DMF.PreviewGrid, Version=6.3.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

Reason:

During the installation time the Client component is not installed, so that this type of error come.

Solution:

Go to the AX setup and select the Client component on Data Import/Export Framework components in add or modify components.

Then install the component, now your problem has been solved.