Using Script Runner to send custom email with a custom user picker field, won't work when null

[Deleted user]

I am setting up a workflow with multiple Custom email being sent via Script Runner.  I am using 2 custom User picker fields, one for the To: section of the email and the other for the Cc: section.

Everything is working fine except when no user is entered into one of the fields, the script throws a java Null error and no email is sent out.  Is there a way around this?  There may be times when no CC user is required, and I was trying to avoid making those fields mandatory and forcing users to always enter a user even if one is not required.

Thanks

[Udo Brand]

It is working on my side: had both custom fields in "To Fields" one was filled, the other empty. The email was sent.

Which version of scriptrunner are you using? I'm on 3.0.10