mountain lion download fails after 53mb

Yes, the area after 53MB has a bad sector on your hard drive and can't write the data any further, this is especially confirmed if you downloaded twice and it stops in the same spot again.

It might be a data cap by your ISP if you have such a thing, or if this only occured once, it could have been a network glitch, try again to confirm. Check in Activitiy Monitor that you have enough free space on the drive, it's ideal to keep below 80% filled on hard drives. If you need to remove stuff, start with Movies copy to a external drive and delete the originals, then reboot so OS X will know the new space is available.

If it stops again, and you don't have any other reason. What you can do is open Disk Utility and select the Macintosh HD partition on the left and Erase > Erase Free Space with the Zero Data option.

What this will do (after some time as it takes quite a bit to perform) is to write Zero's across all the Empty or Free to be overwritten space on your Macintosh HD boot partition (not your data), in the process it checks the write for confirmation (which if it doesn't work) on bad sectors the hard drive will map off that bad sector, never to be written to again.

After this has completed, reboot the machine and try your download again.

I have exactly the same problem download stops at 53MB. It gives error message download failed check internet connection.

I tried the suggestion recommended but erase free space is greyed out on my machine.

I repaired ACLs. which showed errors on verification. but that did not help either.

Hard drive has plenty of space.

Pretty drastic recommendation. Odd that my Google search on this topic found this thread. On THREE different machines my download fails/stops at 53.25MB. Guess all three have bad blocks right at that point...

Or maybe the CDN used to distribute has some sort of checkpoint that's failing... Or there's something wrong with the image being distributed to the CDN.

Hmm, then there's THIS thread...

any one else in the UK having mountain lion download problems, on both my i Mac and mac book air the download freezes at 53.25mb and then fails after short while.

I managed to get through this issue after reading the problems that people were having in the UK.

I downloaded the VPN Shield app from the App store. Paid my $0.99 for a weeks subscription and used it to do the download.

It failed a couple of times but it did checkpoint so I eventually got the download to complete although it was very slow.

There is something very peculiar with the Mountain Lion update or a change in the way the App store delivers the update. I have downloaded at least 3 apps from the store that have been over the 4Gb size of this update. All of them completed successfully in the past.

If this issue is effecting some carriers like BT in the UK and Telstra Bigpond cable (my service) then Apple have done something non standard at the app store to make this now carrier service technology dependent.

I copied the download executable to my second hard drive so I can now move it to my other MacBooks from my iMac

I sincerely hope Apple have not dome something silly at the app store to make large executables fail for some carriers.