Just a very quick one with Preview5.
I encountered this gotcha whereby the project's name in the solution explorer doesn't match that of the folder name.
I'd had a change of heart on the project name but of course the folder on disk doesn't change automatically.
Once I'd renamed the folder and then proceeded to fix the path in the .sln file this error went away.
tl;dr project folder name and project name in the solution explorer seemingly have to match up at present