Q: everytime i try to sign in on FaceTime is never works

Are you able to sign in again with that Apple ID anywhere else?

I had a similar problem to this on my iPhone in the app store, but never found a fix. Hope you not have my luck--I never got my purchases back but am not going on Apple Support again.

Is it saying your ID is incorrect, or is it doing something else like never actually doing anything?

Can you go into preferences? If so, what does it say where your account would be at the top?

Please take each of the following steps that you haven't already tried. Stop when the problem is resolved.

1. Quit the application. Force quit if necessary.

Relaunch it by holding down the shift key and clicking its icon. That action will prevent the last window state from being reloaded.

2. If a McAfee "anti-virus" product is installed, remove it by following these instructions.

Note that if you have already tried to uninstall the software, you may have to reinstall it in order to finish the job. If you have a different version of the product, the procedure may be different.

Back up all data before making any changes. Never install any "anti-virus" or "anti-malware" software again.

3. If you synchronize Contacts with one or more network services such as iCloud or Google, please disable all the contact accounts in the iCloud and/or Internet Accounts pane of System Preferences. When prompted to confirm, choose to delete the contacts from the Mac. They'll still be on the servers and on your other devices.

Log out or restart the computer.

If the problem is now resolved, re-enable the accounts one at a time, wait for the network contacts to reappear, and test after each step.

Credit for this observation to ASC member tomconrad.