Why F12 key opens "Object Browser Window" instead actual Code Definition?

Problem:

Before some days i faced wired problem while working with my project. In my project solution i made different project for data access layer and used data access layer reference to another project so when i pressed F12 key or “Go To Definition” then i redirect to “Object Browser Window” instead actual code definition.

Solution:

After googling, i come to know that it was happening due to “mismatch framework version of different projects”. Firstly my entire project was in framework 3.5 but after some reason i need to update my one project version to 4.0 and i remained my data access layer as it is 3.5. So due to mismatch version it opens object browser window.