The message to inviting an existing user to a site is confusing.

Problem Definition

If a user is already on a site, it will still pop up the message below when the user is invited.

The message is like this:

You've invited 1 user
We'll take care of the rest.

The message is confusing because the user does not need to be invited.

Suggested Solution

Update the message to indicate explicitly that the user is already there. Example:

"You do not need to invite user.email@domain.com because the user is already on your site."