Hey there! The reason you are unable to save a new trigger email is due to the fact that you've created the new date-related email using Emma's old editor. There's currently an issue that prevents any new trigger in the Classic editor from being activated, which our development team has decided not to fix. Instead, we're spending those development hours shoring up our Drag and Drop Editor and other application functions. I know it is tough to learn that a problem will not be fixed, but our Classic Editor will be retired in the near future and it is more pressing that our Drag and Drop Editor experience be as solid as possible.
If you haven't done so for this specific account, I'd recommend to enable to new drag & drop editor, which will allow you to recreate the welcome email, and then set up the trigger without the error message. I hope this helps!
I’m marking this topic as “Not a problem” since we expect there to be limitations in the classic editor. While yes, it’s a problem for that editor, since we don’t support that editor anymore, it isn’t a problem with the current Emma features we support.