Can' get a Mac album into Lightroom!

I am just new with Lightroom....I moved an album from mac photos to lightroom, then deleted it as I forgot to delete all the doubles & images not need anymore. I then tried to move the album back into lightroom & a message came up saying that the album is already in lightroom yet I can't see it.

I have tried severl different ways of placing that album in but to no avail....all the other albums went across smoothly.

Can anyone help please.

Thank you