When we create an Event and send invitations, there is no opportunity to write a message.

however the notification email says "Below is a message sent by (event creator)". Obviously this is blank because the event creator can't write a message

is this a bug? Should we be able to write a message? I think I remember you could previously write a message when you sent the invites.

But at the moment the email is inconsistent with the Event invitation.

For Group events the email notification is correct (i.e. it doesn't mention a message)

Hi, Susan.

You're right, there should be no "Message:" text in this invitation as there is no possibility to add text in it.
I'll report it to our developers.

Hi, Susan.

Please, make safe copy of those files:

ROOT/components/com_community/templates/default/email.events.invite.html.php
ROOT/components/com_community/templates/default/email.events.invite.text.php
ROOT/language/en-GB/en-GB.com_community.ini

Then replace original files with patched ones from package.

This fix will remove spare "Message:" text from event invitation.