Apple - What should I do when "An error has occurred" when downloading Lion?

I have sorted the issue. I just had to use a different router. The BT Business hub that I previously been using had a problem on it which prevented anything above 2GB do loose connection. This would explain other problems as well.

I had a similar event. I was able to solve the problem by:

  1. Signing out the app store
  2. Closing app store
  3. Clearing cookies in safari (evidently app store uses safari's cookies)
  4. Reopen app store
  5. Sign-in to the App Store
  6. Press Option and click Purchases
  7. Click Resume on OS X Mountain Lion under Other Purchases

Maybe this will help?

Because a lot of Mac users are probably doing the same download now. It's probably overloaded. After all 4 GB is a good bit bigger than an iTunes song or an iOS app.