[Dovecot] during change sql password on squirrelmail

Hello

I use squirrelmail1.4.20, compatible2, change_sql plugin, dovecot, postfix, mysql,virtualuser.

I can change my email password successfully on squirrelmail. When I change my password the squirrelmail throw me a page which contains an error as followings;

"This page request could not be verified and appears to have expired."

how can I correct this issue?