I am trying to download the latest version of Xcode from the AppStore so I can continue with my development. I am on a MBP 2016 touch-bar running MacOS High Sierra 10.13.4. I did a lot of digging and can't seem to find anything recent or something that works.

Xcode will download part of the way, but if I disconnect from the WiFi or leave my computer closed for too long it will tell me "An error has occurred" when I come back to it to check on it. The "An error has occurred" message will not go away to let me start up the download again. The only way to fix this (that I know of) is to completely restart my computer. This causes all my download progress to be lost (I live in a country with really bad internet, so I can't just download it in an hour like in America)

I've tried:

  • Restarting my computer (this works but I lose all my download progress)
  • resetting the storedownloadd in the activity monitor
  • activating the debug menu (it doesn't activate no matter what I tried)
  • signing out and signing back in

How do I force the download to restart and get rid of "An error has occurred" message?

1 Answer 1


I helped someone about three weeks ago with the same issue. What worked for them was resetting the System Management Controller and then starting the download again, but this time with their energy saver settings temporarily changed so that their MBP did not go to sleep at all.

Resetting the SMC

To reset the SMC on your model MBP, follow these steps:

  1. Shut down your MBP
  2. Unplug the power cable from your Mac
  3. For 10 seconds, press and hold at the same time the shiftcontroloption keys (on the left side of the built-in keyboard) and the power button
  4. After 10 seconds let go of all keys and the power button
  5. Plug in the power cable
  6. Turn your MBP back on with the power button.

Temporarily change your Energy Saver settings

Now ensure your Energy Saver settings (Apple > System Preferences > Energy Saver) mimic the following:

enter image description here

You can change your settings back again after the download works. If it doesn't work, then you'll know it wasn't some sort of power management issue at your end interrupting the download.

Of course, it goes without saying that you should keep your MBP connected to an AC power source (i.e. the Power Adapter) while trying this.

  • Ok, let me try it. Give me ten minutes. Commented Apr 11, 2018 at 10:09
  • Yay!!! It worked! what do you think was causing the problem? Commented Apr 11, 2018 at 10:15
  • Just a quick update, I ended up going to the Apple Developer and downloading the .xip straight from the site. It provided a much faster method of download and ended up only taking about 6 hours to download. I still appreciate the help, and you actually did help me solve my problem but the Developer site had a faster download speed. Commented Apr 18, 2018 at 10:07
  • That's great, I'm glad you got it sorted! :)
    – Monomeeth
    Commented Apr 18, 2018 at 10:11

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