Enabling Automation Permissions
Tired of seeing this error?
It occurs when Porterhouse has been denied the ability to control the Messages app. But you can fix it :) Here is how...
Open System Preferences
Open the Security & Privacy pane
At the top select "Privacy" > Scroll down to "Automation" and find Porterhouse. Make sure "System Events" and "Messages" are checked.
That should do it, go back and send your message.