Q: El Capitan 10.11.5 wifi issues

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 download and run EtreCheck, created by one of own helpers here in ASC. It is a diagnostic tool that's very useful to us in finding problems. Also it will give us further specs on your Mac. After it runs post the log file here. It will contain no personal information.

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

Take the applicable steps in this support article.

Step 2

The Wireless Diagnostics program generates a large file of information about your system, which would be used by Apple Engineering in case of a support incident. Don't post the contents here.

Be sure to test on more than one Wi-Fi network, if at all possible. A desktop computer can be tested with a mobile hotspot, such as the hotspot created by a cell phone. If the problem only exists on one network, then the access point of that network should be the focus of your attention, not the computer.

Step 3

If your model supports AirDrop (most do), open the AirDrop window and select

          Allow me to be discovered by: No One

Step 4

Disconnect all USB 3 devices, and also all external displays if the Mac has one built in. If you don't know which devices are USB 3, disconnect all USB devices except keyboard and mouse.

Step 5

If you're not using a wireless keyboard or trackpad, disable Bluetooth by selecting Turn Bluetooth Off from the menu with the Bluetooth icon. If you don't have that menu, open the Bluetooth preference pane in System Preferences and check the box marked Show Bluetooth in menu bar. Test. If you find that Wi-Fi works better with Bluetooth disabled, you should use the 5 GHz Wi-Fi band. Your router may not support it; in that case, you need a new router.

Step 6

Open the Energy Saver pane in System Preferences and unlock the settings, if necessary. Select the Power Adapter  tab, if there is one. Uncheck the box marked

          Wake for Wi-Fi network access

if it's checked.

Step 7

Open the Network pane in System Preferences and make a note of your settings in the Wi-Fi service. It may be helpful to take screenshots of the various tabs in the preference pane. If the preference pane is locked, unlock it by clicking the padlock icon and entering your administrator password. Delete Wi-Fi from the service list on the left by selecting it and clicking the minus-sign button at the bottom. Then recreate the service by clicking the plus-sign button and following the prompts.

Step 8

In the Wi-Fi settings, select

          Advanced... ▹ TCP/IP ▹ Configure IPv6: Link-local only

Click OK and then Apply.

Step 9

Reset the System Management Controller.

Step 10

Reset the PRAM.

Step 11

Launch the Keychain Access application. Search for and delete all AirPort network password items that refer to the network. Make a note of the password first. Turn Wi-Fi off and then back on. You'll be prompted for the password when you reconnect. Save it in the keychain.

Step 12

Disconnect all wired peripherals except those needed to start up, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and 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. 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. If the problem is (temporarily) resolved, stop here and post your results.

Step 13

Reinstall the OS. The linked support article refers to OS X 10.11 ("El Capitan"), but the procedure is the same for OS X 10.7 ("Lion") and later. You may need an Ethernet connection in order to carry out this step.

Step 14

Make a "Genius" appointment at an Apple Store, or go to another authorized service center.

Detach the hub and see if that helps.

I can't wait to find out how you managed to "detach a hub" that doesn't exist.

Did you reboot your router and/or modem first see if that fixed your issue. I found when we are having WiFi issues, doing this usually fixes them, but not always. It's the first thing I do, and so easy. My next step is to call my ISP and have them test things from their end. If those don't work, then I come over here and look for solutions.

Is this still fixed for you? I am having exactly the same issue with the same build. Thanks!