App Store Issues (e.g. 403 Forbidden Error)

Fletcher's Avatar


18 Sep, 2017 06:47 PM

Several users have written in with difficulty purchasing upgrades. They report receiving an error from the App Store "403 Forbidden".

As best as I can tell, this is NOT an issue with Composer, but rather with one of the following:

  • The network connection between your computer and the App Store
  • Using a proxy between you and the App Store with an incorrect configuration
  • An improperly configured anti-virus program blocking access

Check out this thread on Apple's Support site for more information and ideas to fix:

By way of explanation, all In-App Purchases are handled by macOS, not by the individual app. Once you click the "Purchase" button, Composer calls a macOS command, basically saying "Purchase item XXX from the App Store". This request is then handled by the "App Store" application (communicating with Apple's Servers, ensuring that you are logged in to the App Store, verifying password, verifying payment information, etc.) I have no ability to interact with any of this once the process starts (which is by design and makes sense).

Once the purchase is approved by Apple, Composer gets a message, effectively saying, "The transaction to purchase item XXX was successful". At this point, Composer displays a dialog, "Upgrade purchased. Restart Composer to take advantage of new features!".

Anything between those two steps happens entirely "behind the scenes", as far as Composer is concerned.

What Composer can do is:

  • Every time you open Composer, it validates that that the expected upgrade items are available in the App Store
  • Part of that validation is to be informed what the listed price is (This information comes from Apple, and is not hard-coded into the App itself). This is displayed in the "Purchase Upgrades" dialog.
  • Validate your App Store receipt to determine which (if any) upgrades have been purchased
  • Request that any previously purchased items be restored -- this can be helpful if you restored an App from a backup before you purchased an upgrade, for example.

I hope this helps explain what's going on. If anyone is helped by the information on that support thread, please let me know what worked for you! Thanks!!!

  1. Support Staff 1 Posted by Fletcher on 19 Sep, 2017 12:55 AM

    Fletcher's Avatar

    Bump to keep this at the top of the list.

  2. 2 Posted by kburke12 on 19 Sep, 2017 01:13 PM

    kburke12's Avatar

    I've tried all the Apple suggestions, no joy. Thoughts? Interested in seeing how many others are having this problem.

  3. Support Staff 3 Posted by Fletcher on 19 Sep, 2017 02:03 PM

    Fletcher's Avatar

    Are you getting the 403? If so, and those don't do it:

    1. Can try on a different network (work, coffee shop, etc).

    2. Contact Apple for support.

    I'm afraid that's all I've got at the moment.

  4. 4 Posted by rwcope2 on 19 Sep, 2017 07:20 PM

    rwcope2's Avatar

    Rebooting my computer solved the 403 error when upgrading to pro.

    I got the 403 error trying upgrade to pro right after I installed from the App Store. I don't use any proxies or VPNs or antivirus software. The advice in the Apple discussion link didn't help either. I also noticed that auto-save wasn't working. After rebooting, all of those problems were solved.

  5. 5 Posted by Paul Solt on 19 Sep, 2017 07:32 PM

    Paul Solt's Avatar

    I also just tested this.

    1. I rebooted
    2. I tried to "Restore Purchases"
    3. App Store made me sign in again
    4. Then Clicked "Buy" button for Pro
    5. Then it asked for finger print (Touch ID) to confirm

    Now it works.

  6. Support Staff 6 Posted by Fletcher on 19 Sep, 2017 07:51 PM

    Fletcher's Avatar

    Glad it worked for both of you!

  7. 7 Posted by Steve Glaser on 20 Sep, 2017 12:21 AM

    Steve Glaser's Avatar

    Rebooting fixed the issue. Not sure why I didn't try that earlier. I guess macOS is just to darn reliable that rebooting is not the first line of defense like it is on Windows.

  8. Support Staff 8 Posted by Fletcher on 20 Sep, 2017 12:27 AM

    Fletcher's Avatar


  9. Support Staff 9 Posted by Fletcher on 21 Sep, 2017 08:39 PM

    Fletcher's Avatar
  10. Support Staff 10 Posted by Fletcher on 28 Oct, 2017 08:22 PM

    Fletcher's Avatar


Reply to this discussion

Internal reply

Formatting help / Preview (switch to plain text) No formatting (switch to Markdown)

Attaching KB article:


Attached Files

You can attach files up to 10MB

If you don't have an account yet, we need to confirm you're human and not a machine trying to post spam.

Keyboard shortcuts


? Show this help
ESC Blurs the current field

Comment Form

r Focus the comment reply box
^ + ↩ Submit the comment

You can use Command ⌘ instead of Control ^ on Mac