You’ve just installed Visual Studio 2017 (Or the very latest .net core SDK), and now when you try to compile an old .net core project you had laying around, you are getting an error similar to the following :
.vs\restore.dg(1,1): error MSB4025: The project file could not be loaded. Data at the root level is invalid. Line 1, position 1.
The issue is actually very very similar to a previous error you would have occured when you installed Visual Studio 2017 RC over the top of Visual Studio 2015. You can read about that issue here.
The fix is very similar, first go to “C:\Program Files\dotnet\sdk” on your machine. You should see a list of SDK versions. The version you are likely looking for is “1.0.0-preview2-003131” if you were previously opening this project in Visual Studio 2015. If you have 2 versions only, then the version you are looking for is the one that is *not* labelled 1.0.0. If you have only 1.0.0, then you probably got this project from someone else so will have to liase with them what version of the SDK you should be installing. Install that SDK and then come back to read on!
In the root of your solution for your project, create a file named “global.json”. Inside that file, place the following contents :
{
"sdk": { "version": "1.0.0-preview2-003131" }
}Where the version is the SDK version from our previous step.
Ensure Visual Studio is closed and now open a command prompt in your solution directory of your project. Run the command “dotnet restore”. You should see a few packages whiz past. After this open your solution again (In Visual Studio 2015), and you should now be able to build successfully!
