Unable to add password to tax return

I have turbotax premier.  I have been unable to add a password to a tax return.  The first message indicated password is case sensitive and have a mini length of 8 and max of 32.  I try again.  Then I get a message that said Turbo Tax Premium for security, your answer should be between 6 and 16 characters.  Still no luck.  I AM NOT TRYING TO RESET A PASSWORD.  I AM TRYING TO ADD A PASSWORD TO A TAX RETURN THAT I FINISHED SEVERAL DAYS AGO.  I HAVE MADE SEVERAL ATTEMPTS. HELP HELP HELP