thing are getting changed day by day and lazy enough to understand these. for example today when I deployed a BizTalk solution I got the error something like missing project resource Please verify that the pipeline strong name is correct and that the pipeline assembly is in the GAC.
upon investigation I realized that now BTS projects are not deployed to the GAC I don’t know but now we have this situation so you have to manually add the project to global Assembly Cache using GaCUtil –I “Assemblyname.dll” once you do that then you application will start working fine. I also learn that now there are two separate GACs one for .NET version 4.0 and one for old .net application. so whenever you get an error like this don’t forget to add your project file to GAC.
In .NET Framework 4.0, the GAC went through a few changes. The GAC was split into two, one for each CLR.
The CLR version used for both .NET Framework 2.0 and .NET Framework 3.5 is CLR 2.0. There was no need in the previous two framework releases to split GAC. The problem of breaking older applications in Net Framework 4.0.
To avoid issues between CLR 2.0 and CLR 4.0 , the GAC is now split into private GAC’s for each runtime.The main change is that CLR v2.0 applications now cannot see CLR v4.0 assemblies in the GAC.
It seems to be because there was a CLR change in .NET 4.0 but not in 2.0 to 3.5. The same thing happened with 1.1 to 2.0 CLR. It seems that the GAC has the ability to store different versions of assemblies as long as they are from the same CLR. They do not want to break old applications.
See the following information in MSDN about the GAC changes in 4.0.
For example, if both .NET 1.1 and .NET 2.0 shared the same GAC, then a .NET 1.1 application, loading an assembly from this shared GAC, could get .NET 2.0 assemblies, thereby breaking the .NET 1.1 application
The CLR version used for both .NET Framework 2.0 and .NET Framework 3.5 is CLR 2.0. As a result of this, there was no need in the previous two framework releases to split the GAC. The problem of breaking older (in this case, .NET 2.0) applications resurfaces in Net Framework 4.0 at which point CLR 4.0 released. Hence, to avoid interference issues between CLR 2.0 and CLR 4.0, the GAC is now split into private GACs for each runtime.
As the CLR is updated in future versions you can expect the same thing. If only the language changes then you can use the same GAC.