i am using version 3.28

i exported database from old server and import to another server. it installed with no problem with surveys as well but when i click to survey for start then i get "500 error Unknown "makeFlashMessage" function". error. 

This function is included in frontend_helper.php

Can you activate debug mode ?
www.limesurvey.org/manual/Debug_mode

i understand my mistake. i explane maybe i can help to someone . when i want to import database to new server first of all i delete all tables from new database after that i import old database . i shouldnt have delete all tables. just import.

thanks for reply

Don't really understand but happy it was fixed now.