download new zorin 8 to upgrade zorin 7

Hello iam traying upgrate my zorin 7 to zorin 8
but when i download it i get the following anwer in Fire fox: /tmp could not be saved, because an unknown error occurred.

Try saving to a different location.

what i supose to to, please keep it simple i am not a computer nerd

Hi mission4unity, sounds like you have not enough space left on your hard drive?

(Had to delete your other post as it was in the wrong section - feel free to add you original question here)