TFS 2013 Configure features after the Upgrade

Hi,

We have upgraded form TFS 2008 to TFS 2013 successfully. I'm trying to configure the features after the Upgrade manually and following this documentation available on MSDN. 

http://msdn.microsoft.com/en-us/library/ff452591.aspx

I have completed the steps 1,3,4 with out any issues as steps 2 and 5 are optional (as I thought  we used  MSF for CMMI template for TFS 2008 projects).  I'm getting the below error(Image 1) when I'm importing the work item types (step 6).

These are the Work items I can see  in our TFS 2008 Environment (Image 2) and in TFS 2013 environments(Image 3). Please let me know how can I resolve the issue, thanks 

Regards,

Rahman.