SQL Server 2014 as is with its CLR Types file does not work with the Spatial Data Type. I did not succeed to make that work. I had to uninstall the CLR Types 2014 and installed CLR Types 2012. That worked.

I also did not find a post on the Internet about someone who has SQL Server 2014 with the combination of a Web site doing some access to a table having some Spatial Data Type. So, there seems be something there.

So, the main components are like this:

SQL Server 2014
IIS 8.5
Windows Server 2012 R2
On the Web server, I installed SQLSysClrTypes.msi 2012
In the project, there is a reference to that file
In the connection string, there is ;Type System Version=SQL Server 2012

As the Spatial Data Type is not supported as is in the .NET SQL Data Client, we need to add this extra support. This is like that for three versions. This is still highly complicated. If there is a simpler way to achieve this, I would very much like to know about it.

At least, if I could use SQLSysClrTypes.msi 2014, that would be better. But, the problem is, when using that version, we cannot add that syntax in the connection string.