Facebook is not working on any of my browsers!

Question

Hi everyone,
I am tired of my facebook not working. It has been almost a 5 months since I had this problem where it keeps saying:
This webpage is not available
Google Chrome cannot reach the website. This is typically caused by network issues, but can also be the result of a misconfigured firewall or proxy server.
Now I get the same result on all my browsers. I have tried many many solutions from removing cache, proxies, hosts.. Nothing works. Even changing my DNS server to 8.8.8.8. Please someone help me lol and yes facebook works on all the computers in my house except mine
Thank you!

Answer 1

You, or someone using your computer, hacked the system to block certain servers, perhaps unknowingly. The file modified is /etc/hosts. Some commercial "anti-virus" software, such as "Avast," may modify this file. If you've installed any such software, I suggest that you remove it according to the developer's instructions before continuing.
The easiest way to fix the hosts file is to restore it from a backup that predates the modification, or to copy the unmodified file from another Mac. If you can't do that, then do as below. Please read this whole message before doing anything.
Back up all data. This is a simple procedure, but if you don't follow the instructions exactly, you could be left with an unbootable system. In that case, you'll have to restore from a backup or reinstall OS X.
If you have more than one user account, you must be logged in as an administrator.
Triple-click anywhere in the line below to select it:
open -a TextEdit /etc/hosts
Copy the selected text to the Clipboard (command-C).
Launch the 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. Click Utilities, then Terminal in the icon grid.
Paste into the Terminal window (command-V). A TextEdit window should open. At the top of the window, you should see this:
# Host Database
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
127.0.0.1                              localhost
255.255.255.255          broadcasthost
::1                                        localhost
fe80::1%lo0                    localhost
Below that, you'll see some other lines. There should be nothing above the first line "##". If you have any doubt about that, STOP and ask for guidance. Make sure you scroll all the way to the bottom of the document. Scroll bars are hidden by default until you actually start scrolling, so you may not realize that you’re not seeing the whole document.
If the contents of the TextEdit window are as described, close it, then enter the following command in the Terminal window in the same way as before (by copy and paste):
sudo sed -i~ '11,$d' /etc/hosts
This time, you'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning to be careful. Confirm. Quit Terminal. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator.
That will fix the hosts file. There is now a copy of the old hosts file with the name "hosts~" in the same folder as "hosts". You can delete the copy if you wish.