Couldn't open Owin example in Visual Studio 2019

[equezada-jej]

I leave this message more as a tip for people looking into this than an actual issue.

When I was trying to open the Owin example in VS2019, it had an error when trying to upgrade it.

(It's in spanish, sorry, but roughly translates to couldn't find the application of which this type of project is based on)

It was then when that I decided to look into the .csproj file to see what it had different from my own Web Form projects.
I noticed that the line:

<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />

was different from mine:

<Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />

so I changed MSBuildToolsPath to MSBuildBinPath and it worked!