.NET not detecting any SQL Server instances

Question

I have been developing a C# / SQL Server application on a Windows 8.1 device for a while, using .NET 4.5.1 and SQL Server 2012 Express. It all worked flawless. Recently, Visual Studio 2015 has been released and I decided to upgrade. I also decided to upgrade my SQL Server 2012 as well, so I backed everything up, uninstalled it and installed SQL Server 2014 Express. After configuring everything and restoring the database backups everything still worked locally as the database connection data was still present in the stored application settings.

When I tested the application on another device I found out that it could no longer connect to the SQL Server instance and it couldn't detect it either using

System.Data.DataTable instances = SqlDataSourceEnumerator.Instance.GetDataSources();

The application couldn't detect the SQL Server instance on my development machine either, which I think is rather strange as it's running local. Several other devices could, however, detect the SQL Server so I don't think it's a firewall related program. The SQL engine service and the browser services were both active.

I decided to upgrade to Windows 10, reset it (clean install, did not install any SQL Server programs) and run my application again, as there are other computers in my network running SQL Server, hoping it would detect those. It didn't. The GetDataSources() method returns an empty DataTable within a split second, while other devices take a few seconds to detect the instances and return a correct list.

Even more stupid is that ODBC Data Source Administrator does detect those network instances, making me think it is a .NET related program.

Summary: two devices do not detect any SQL Server instances (even local), while the other devices in the network do.

Answer 1

I have decided to go with this ODBC implementation as it is working correctly and an async/await update can be implemented so it won't block the UI.

Before choosing this implementation, I also poked around with another project using the SqlDataSourceEnumerator class, which worked perfectly. Its Target framework property was set to .NET Framework 2.0. I discovered that the SqlDataSourceEnumerator gives the expected results (on my machine) when the .NET target version is 3.5 or lower. Something in the .NET implementation has probably changed over time, causing it to stop working in some specific conditions.

Edit: on my machine I have installed SQL Server 2012 again, and everything (except for the detection, will use ODBC) is working fine again. I want to thank everyone for their input.