ankurverma500 wrote:
I am not able to login into my MAC PC through my Apple ID But I am able to login in my Apple ID in browser and in my iPhone.
My MAC is neither displaying that the Password you have entered is wrong.
Its just saying "an unknown error occurred."
You had to login with your Apple ID/password to make a post in these forums (?)
Try a SafeBoot https://support.apple.com/en-us/HT201262
Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc. Login and test.
if you continue to have an issue—
Contact Apple for help with Apple ID account security - Apple Support
https://support.apple.com/en-us/HT204169