There is an error in XML document (2, 2): Visual Studio, SSRS Project file errors (VS2015-VS2017)

I resolved the problem by deleting the MyProjectName.rptproj.user file

Try to delete *.rptproj.rsuser file and reload project. It works for Visual Studio 2019 as well.

Or just create new project and add exsting items (reports, data sources) inside it.

The problem appears to be in the .suo and .csproj.user files that are left over from previous versions of Visual Studio. Delete these files and then the SSRS project should load successfully in VS2017.