**Describe the bug** This may be a problem with the dotnet tool, but I thought I will inform you as well. Running this command ``` dotnet list package --vulnerable --include-transitive --source https://api.nuget.org/v3/index.json ``` fails with this error: ``` warn : An invalid cache entry was found for URL 'https://api.nuget.org/v3/registration5-gz-semver2/system.io.abstractions.testinghelpers/page/1.2.0/1.4.0.76.json' and will be replaced. warn : '' is not a valid version string. error: '' is not a valid version string. ``` This error only occurs when "TestableIO.System.IO.Abstractions.TestingHelpers" is added as package. **To Reproduce** - Get the repro repo from here: https://github.com/Dave-Senn/ReproListPackages - Run the command Issue created in the sdk repo: https://github.com/dotnet/sdk/issues/44840