I encountered the same issue, and the solution for me was to do the same as the poster's comment, but I thought I would add a more detailed explanation.

Find where the Visual Studio installer is located in your program files. For me, this was in C:\Program Files (x86)\Microsoft Visual Studio.

Within that directory, rename or delete the folder called "Installer" then rerun whichever Visual Studio setup application you need from here: https://visualstudio.microsoft.com/downloads/

This got rid of the error for me and allowed me to properly install VS.