How to correctly and safely update versions of "important" assemblies in ASP.NET MVC?

Question

ASP.NET

Today I went to the Nugget Manager and saw that a whole bunch of packages needed updating, including mvc builds, razor and other files important for the project. I was delighted and clicked "update all". After the update, the project stopped running and started giving errors about dependencies. In the web.config, which is located in ~/views, I corrected the assembly versions - another error began to pop up. I got scared and rolled back all the changes. Actually the question is: how to correctly and safely update the versions of "important" assemblies?

Answer 1

Answering my own question: the project was trying to upgrade to MVC5. Detailed instructions for this process: http://www.asp.net/mvc/tutorials/mvc-5/how-to-upgrade-an-aspnet-mvc-4-and-web-api-project-to-aspnet- mvc-5-and-web-api-2