I can't download apps from the App Store. What's the fix?

The first thing you want to do is to update iTunes to 12.1.0.50...

That may clear up your issues completely.

Cheers,

GB

Please test after taking each of the following steps that you haven't already tried. Stop when the problem is resolved. Back up all data before making any changes.

Step 1

Rebuild the Spotlight index. If you try to search now from the magnifying-glass icon in the top right corner of the display, there will be an indication that indexing is in progress.

Step 2

Unlock the Network preference pane, if necessary, by clicking the lock icon in the lower left corner and entering your password. Cllck Advanced, open the DNS tab, and change the server addresses to the following:

8.8.8.8

8.8.4.4

That's Google DNS. Click OK, then Apply.

Step 3

Quit the App Store if it's running. Force quit if necessary.

Please triple-click anywhere in the line below on this page to select it:

defaults write -app "App Store" ShowDebugMenu YES

Copy the selected text to the Clipboard by pressing the key combination command-C.

Launch the built-in Terminal application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

Paste into the Terminal window by pressing the key combination command-V. I've tested these instructions only with the Safari web browser. If you use another browser, you may have to press the return key after pasting.

Wait for a new line ending in a dollar sign ($) to appear below what you entered. You can then quit Terminal.

Launch the App Store. There should now be a menu labeled Debug in the menu bar at the top of the screen. From that menu, select

Reset Application

Quit again and relaunch. Test.

Optionally, remove the Debug menu by quitting the App Store and entering the command below in the same way as before:

defaults delete -app "App Store" ShowDebugMenu

Launch the Console application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

Select

/var/log ▹ appstore.log

from the hierarchical list on the left. If you don't see that list, select

View ▹ Show Log List

from the menu bar.

Each message in the log begins with the date and time when it was entered. Select the messages from the last installation or update attempt, starting from the time when you initiated it. If you're not sure when that was, click the Clear Display button in the toolbar of the Console window and then try the installation again.

Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message (command-V).

If there are runs of repeated messages, post only one example of each. Don’t post many repetitions of the same message.

☞ The log contains a vast amount of information, almost all of it useless for solving any particular problem. When posting a log extract, be selective. A few dozen lines are almost always more than enough.

Please don't indiscriminately dump thousands of lines from the log into this discussion.

Please don't post screenshots of log messages—post the text.

☞ Some private information, such as your name, may appear in the log. Anonymize before posting.

The instructions must be carried out as an administrator. If you have only one user account, you are the administrator. If you still can't find the log, change the selection to All Messages and continue from there.

Please read this whole message before doing anything.

This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.

Step 1

The purpose of this step is to determine whether the problem is localized to your user account.

Enable guest logins* and log in as Guest. Don't use the Safari-only “Guest User” login created by “Find My Mac.”

While logged in as Guest, you won’t have access to any of your documents or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this behavior; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.

Test while logged in as Guest. Same problem?

After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.

*Note: If you’ve activated “Find My Mac” or FileVault, then you can’t enable the Guest account. The “Guest User” login created by “Find My Mac” is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.

Step 2

The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.

Please take this step regardless of the results of Step 1.

Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and log in to the account with the problem. You must hold down the shift key twice: once when you turn on the computer, and again when you log in.

Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.

Safe mode is much slower to start up and run than normal, with limited graphics performance, and some things won’t work at all, including sound output and Wi-Fi on certain models. The next normal startup may also be somewhat slow.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

Test while in safe mode. Same problem?

After testing, restart as usual (not in safe mode) and verify that you still have the problem. Post the results of Steps 1 and 2.

Would that be correct?

No. If you haven't already done so, connect to a different network, such as a public hotspot, and try again. If there's no change, see below.

Back up all data.

Triple-click the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination command-C:

/Users/Shared/adi

In the Finder, select

Go ▹ Go to Folder...

from the menu bar and paste into the box that opens by pressing command-V. You won't see what you pasted because a line break is included. Press return. A folder may open. If it does, move the contents to the Desktop, leaving the folder open. Restart the computer, then sign in to the App Store and test. If the problem is solved, delete the files you moved.