title: CryptographicException when trying to open a certificate from dotnetcore
body: <p>When running dotnet core in docker, i recently got this  cryptic  dotnet exception .</p>
  <p>System.Security.Cryptography.CryptographicException: Unix LocalMachine X509Store is limited to the Root and CertificateAuthority stores.|
  ---\u003e System.PlatformNotSupportedException: Unix LocalMachine X509Store is limited to the Root and CertificateAuthority stores.|</p>
  <p>Below exception, I got when I tried to open a certificate from my docker certificate store
  x509Store.Open(OpenFlags.ReadOnly)</p>
  <p>The cause of the error was that the certificate was missing from my docker instance.</p>
  <p>The exception thrown is not at all helpfull</p>