Why is it impossible to connect to the database when transferring a site to ASP.NET MVC from a computer to a VPS?

Question

ASP.NET

There is a local computer with an ASP.NET MVC 4 project that uses the Entity Framework to work with the database. There is also a remote VPS. On VPS (Windows Server 2012) I installed IIS, FTP and SQL Server Express.
I transfer files from a computer to a VPS, change the connection string - it says that the connection string parameter is not correct. I tried in every possible way to pervert with the line - I did not get the result. I decided to create a test ASP.NET MVC project, where the Entity Framework itself generates a connection string, as a result I got an error connecting to SQL Server.
On the VPS, I connect to SQL Server through Management Studio without any problems. Thus, everything works on the local computer, nothing works on the VPS, except for the ability to connect through Management Studo.
Can you suggest what could be the problem?
UPD.
- SQL Server service is running
- TCP/IP is allowed in Configuration Manager
- Same error if you open the site through the VPS internal browser

Answer 1

as a guess
- on the VPS in Services check that the SQL service is running
- see what protocols are allowed to connect (SQL Server Configuration Manager) - maybe you only have Shared Memory allowed on the server and the client (EF) is knocking on TCP/IP