Exec directory error ( .dll & .rhp confilct )

Hi everyone,

When I try to lookup SampleCs files in GitHub in my Visual Studio 2019 Mac, I am getting error on the line:
<Exec WorkingDirectory="$(OutDir)" Command="$(PostBuildEvent)" />

Screen Shot 2020-03-13 at 15.35.52
How can I solve this issue?

Thanks in advance,
-Oğuzhan