what is this error i'm getting ?

[dvir]

hi to all , 

i'm getting this message while navigating in my BO :

 

public_html/classes/controller/AdminController.php

[2] Cannot modify header information - headers already sent by (output started at /home/adobesa1/public_html/themes/default-bootstrap/modules/blockcart/translations/he.php:1)

 

what is this error and how can i fix it ?

 

thanks 

 

 

 

 

 

[dvir]

never mind  

i've solved it 

 

solution :

need to change the encoding of the file to "UTF-8 WITHOUT BOM"