I see this often with the imported fruit from Mexico.
Some speculation is that the voids are caused by lack of Calcium. You should ask what their soil pH is and if they fertilize their tree regularly.
I usually cut away the voids and enjoy the rest, but on that fruit it appears to be ripening from the inside to the outside, and the inside is almost at the spoilage stage. That is something you see often when the tree does not get Calcium.