Q: Pages not displayed properly

Your screenshots are from another browser. Is Safari affected?

Have you installed something called "Avast?"

Safari - Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues

Safari doesn't load a page or webpage items are missing

Safari/other browsers – Website not loading

Please read this whole message before doing anything.

This procedure is a diagnostic test. It’s unlikely to solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.

The purpose of the test is to determine whether the problem is caused by third-party software that loads 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.

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.

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 login 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 the test.

Please start up in Recovery mode. In the OS X Utilities screen, select Get Help Online. A clean copy of Safari will launch. No plugins, such as Flash, will be available. While in Recovery, you'll have no access to your saved bookmarks or passwords, so make a note of those before you begin, if they're needed for the test.

Test. After testing, restart as usual and post the results.

Please back up all data.

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.

In Safari, select

          Safari ▹ Preferences... ▹ Privacy ▹ Remove All Website Data

and confirm. If you’re using another browser, empty the cache. Test. Any difference?

Notes:

1. If you lose Internet access after making the above change to your network settings, delete the Google servers in the  Network preference pane, then select the TCP/IP tab and click Renew DHCP Lease. That should restore the original DNS settings; otherwise restore them yourself. Remember that you must click Apply in order for any changes to take effect.

2. I don't use Google DNS myself, though I have tested it, and I'm not recommending it or any other DNS provider; the server addresses are offered merely for testing purposes. There may be privacy and technical issues involved in using that service, which you should investigate personally before you decide whether to keep the settings. Other public DNS services exist.

Please back up all data.

Launch the Keychain Access 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.

From the Category list in the lower left corner of the window, select My Certificates. In the list of certificates on the right, there may be one or more have a name that begins with "VeriSign". Export each such certificate by dragging it to the Desktop, then delete it from the keychain. If there are any certificates marked with a red "X" as expired or invalid, regardless of name, delete them without exporting.

Next, select Certificates from the Category list. Look carefully at the list of certificates in the right side of the window. If any of them has a blue-and-white plus sign in the icon, double-click it. An inspection window will open. Click the disclosure triangle labeled Trust to disclose the trust settings for the certificate. From the menu labeled

          Secure Sockets Layer (SSL)

select

          no value specified

Close the inspection window. You'll be prompted for your administrator password to update the settings.

Now open the same inspection window again, and select

          When using this certificate: Use System Defaults

Save the change in the same way as before.

Revert all the certificates with non-default trust settings. Never again change any of those settings.

Again, delete all expired or invalid certificates.

Log out or restart the computer. Test. If all is now well, back up again, then delete the certificates you exported to the Desktop.