Is it possible to download the Mac file anywhere other than Mega? I just got halfway through downloading, then it crashed, then it told me that I was over my free monthly limit and would have to pay them to fail to download files in the future.
I suggest you google for the solution, it doesn't look like the game's problem.
See if this helps
https://www.statsilk.com/support/faq/resolving-mac-only-error-file-damaged-and-s...