Visual Studio 2015 use NuGet install library, make a mistake, ask for help!!!!!!!!!!-CodePudding

I use NuGet install in MVS2015 library, it prompts

Unable to add references to the "MathNet. Numerics,"

For help!

Install other library is also the case

 
Is installing MathNet. Numerics 4.0.0, 
Are package "MathNet. Numerics. 4.0.0" is added to the folder "D: \ Learning \ \ SRTP_Pro1 \ c + + packages" 
Has put the package "MathNet. Numerics. 4.0.0" is added to the folder "D: \ Learning \ \ c + + SRTP_Pro1 \ packages" 
Installation failed, are rolled back... 
Package "MathNet. Numerics. 4.0.0" does not exist in a project "SRTP_Pro1" 
Is from the folder "D: \ Learning \ \ SRTP_Pro1 \ c + + packages" to remove the package "MathNet. Numerics. 4.0.0" 
From the folder "D: \ Learning \ \ SRTP_Pro1 \ c + + packages" to remove the package "MathNet. Numerics. 4.0.0" 
Unable to add references to the "MathNet. Numerics,"