I provided four solutions are in this article, which I found thru Google search. Also I mentioned in the article, 4th solution is helped me, but it works me one time only, after clear Visual studio Cache. If I try to add the items to the toolbox, again Visual studio closed automatically.
Now I come up with other solution, it fixed my issue permanently.
When I checked in the "Event Viewer" of my system, it logged the Error as
.NET Runtime version 2.0.50727.3607 - Fatal Execution Engine Error (7A036050) (80131506)
Microsoft released the Fix for this issue. You can download the fix from this the following link,
Download the relevant fix depends on your VS application Architecture and install it.
After install this fix, restart your system. Then run your Visual Studio. Now you can add the item many times to the toolbox.