Not enough space at 98% of burning process

Burning my movies with menu's on a LG blu-ray burner on my Macbook Pro goes perfect until 98% of step 5.

Then the notification "not enough space" is in the left bottom side and everything stops.

I've clicked "fit to disc size" otherwise it won't start the burn process at all.

So I don't know what's wrong, please advise!

Kind regards,

Jorge Wolters