NuGet Warning NU3027

Package 'SamplePackage v1.0.0' from source 'https://contoso.com/index.json': The signature should be timestamped to enable long-term signature validity after the certificate has expired.

Issue

The package signature does not contain a timestamp.

Solution

For long term signature validity, please request the package author to re-sign the package using the nuget sign command as described in NuGet docs using the -Timestamper option.