Ran into an issue where I could not open rptproj files with Visual Studio 2019. Since these were old SSRS reports, I thought I’d try opening them with Visual Studio 2013. Didn’t work either. Visual Studio 2012? Nope.
Did some more research and eventually found out that this is not a Visual Studio issue. Apparently, to open rptproj files with Visual Studio, you need to install the corresponding Microsoft SQL Server Data Tools - Business Intelligence package. Would not have figured that out had it not been for this post.
So I went here to download the SQL Server Data Tools BI package. Installed it. And now I can open the SSRS solution/project in Visual Studio 2012.