I have a dishwasher with some obvious broken pieces (see attached photos) but I need help identifying them and how they go back together. The blue round piece somehow melted but I can't tell if the other parts of the lower arm assembly are broken. I am especially concerned of the white piece that accepts the arm. Is there a way to tell if it is broken? I can't figure out how this happened but the blue disc piece is melted and pieces are missing from it. Any help would greatly appreciated.

Thank you,
Edd