Quote:
I have tried to uninstall the package and reinstall.
you can try as many times as you want, it will never work, because the error message tells you.
read carefully:
Quote:
Install-Package : Could not install package 'ReportUnit 1.2.1'. You are trying to install this package into a project that targets '.NETFramework,Version=v4.5', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.
it also gives you the solution in last sentence.