[BTS] The type or namespace name 'XLANGs' does not exist in the namespace 'Microsoft'

Error 10 The type or namespace name 'XLANGs' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?) D:\Users\CN-ADMIN-EX2\Projects\CNMOT.OMS\MOT.Integration.Common.Library\SAP\IDocDisassembler.cs 47 46 MOT.Integration.Common.Library

Reason: If you use VS2010 to migration a VS2008 BizTalk Project. Please check the new project was builed in .net 4.0.