everytime I try to sign in to my apple id it keeps saying that an unknown error has occured. why does it do that?

Some things you can try. Do you have access to another WiFi network where you can try? That has worked for several people.

Try a restart.

Restart your iPhone, iPad, or iPod touch         

Try a forced restart.

Reset Device.      

Settings was 1 in red circle. When I hit it I go to Update Apple ID Settings. I get this message: Some account services require you to sign in again. I hit continue and go to Apple ID Password. I enter the correct password and get this message:

Verification failed

An unknown error occurred

OK

Did you try what I posted above?