Could not load file or assembly Microsoft.Practices.EnterpriseLibrary.Common, Version=4.1.0.0 ASP.NET 4.0

Platform : ASP.NET 4.0

Application : A website project with a Datalib ClassLibrary attached to it

Dependencies:

I am getting the error at localhost. I haven't checked online yet.

The whole thing was working at ASP.NET 3.5 and now when i upgraded to ASP.NET 4.0 I get the following error.

The Stack Trace is

At VisualStudio 2010, the error is

This is not happening everytime.

The first runs always 开发者_JAVA百科show this error.

What could be wrong?

I guess it's looking in the wrong place for some reason... try adding this assembly to the server GAC and remove it from the BIN folder.