I recently need to do an upgrade on my project from .net 3.5 to .net 4 and connect to the new SQL server 2008 R2. After I upgrade and compile, it throws these 2 errors:

Interop type 'Microsoft.SqlServer.Dts.Runtime.Wrapper.ApplicationClass' cannot be embedded. Use the applicable interface instead. 

The type 'Microsoft.SqlServer.Dts.Runtime.Wrapper.ApplicationClass' has no constructors defined

the code throw out this error is on the ApplicationClass:
IDTSApplication90 app = new ApplicationClass();

I have this dll in the bin folder: Microsoft.SqlServer.DTSRuntimeWrap.dll
This dll's version is 9.0.242.0

I think .NET 4 doesn't like it. So I ask our DBA to search this file in the server to look for version 10. She told me this file doesn't exist in the sql server.

What do I do to resolve this issue?