Unable to login to gtalk, but same userID pwd work when gmail is Accessed

Unable to login to gtalk, but same userID pwd work when gmail is Accessed ?

Some times we unable to login gtalk thus we can access gmail.
like below error will appears

Simply we have to change some setting in Google accounts.

once we enable 2-step verification is ON 
like below

click on EDIT (2-step verfication)
we will get one screen

Check the application available or not ... click on revoke

it that application not available name that application in below generate password
click on Generate password

you will get auto generated password

copy and paste in your password 
now u can able to login gtalk.

This error will raise... so we have to revoke all other application with directly integrate to google.....