Today I got the error below :

after typing :

I don’t know why ? but I know how to solve it.
First of all let’s disable password authentication :
Stop your MySQL daemon:

or

Then run the following command line in background :

Secondly run :

Finally, In your MySQL command line prompt issue the following command:

Password is now reset to my_password. So just restart your MySQL server using :

or

and use your new password to authenticate :

All that remains is to enter your password.