Migrate browser based InfoPath Forms with code behind from MOSS 2007 to SharePoint 2013

What?

How to successfully migrate browser based InfoPath Forms with code behind from MOSS 2007 to SharePoint 2013?

In this post I will try to explain some of the obstacles that you might be hit with and the ways to get around them.

Please use this is a general guide to understand the overall migration process.

InfoPath assembly Microsoft.Office.InfoPath.Server.dll missing in SharePoint 2013?

What?

I am working on migrating an InfoPath Form Solution with code-behind from MOSS 2007 to SharePoint 2013.

After the old solution was upgraded to Visual Studio 2012 on a SharePoint 2013 server, Visual Studio complained that the assembly Microsoft.Office.InfoPath.Server.dll could not be found.

Where?

Not in GAC
Not in 15\Bin
Not in 15\ISAPI

It is found in C:\Program Files\Microsoft Office Servers\15.0\Bin