Cant login webfig after 5.26 to 6.4 (winbox works)

RouterOS Beginner Basics
1

After an upgrade from 5.26 to 6.4 i can;t login via webfig (ERROR: Internal Server Error) , i can use winbox , i tried changing password all ok.. webfig just dies.

Any special instruction ?

2

fixed we need to /webfig not the default (webbox) /