In Sitecore 9.1.1 XP1 on CM server
Forms Extension 2.2.1, Send Email submit action gives error:
ERROR Object reference not set to an instance of object.
Exception: System.NullReferenceException
Message: Object reference not set to an instance of an object.
Source: Feature.FormsExtensions
at Feature.FormsExtensions.SubmitActions.SendEmail.SendEmailBase`1.SendMail(ContactIdentifier toContact, Dictionary`2 customTokens, Guid message)
at Feature.FormsExtensions.SubmitActions.SendEmail.SendEmailBase`1.Execute(T data, FormSubmitContext formSubmitContext)
Forms Extension works fine on our XP0 test server.
I really have no idea where to start to look. Any ideas?