.NET Framework error when running K2 App Deployment tool
During App Deployment, a .NET Framework error message at the K2 Server URL screen appears when you click the Next or Test button.
System.NullReferenceException: Object reference not set to an instance of an object.
at SourceCode.SetupManager.UI.Panels.MetaDataDocUrlPanel.Sha512Incompatibility(String url)
The K2 App Deployment tool attempted to reach K2 AutoDiscover URL but the connection was terminated due to an invalid certificate. In this case, a special wildcard certificate was used during the initial K2 setup (internet connection is required to validate the certificate).
Allow internet access between K2 and SharePoint to resolve the issue.