how to rename menu in vtiger crm am trying to do that am getting warnings

Question

I am trying to rename the menu items in v tiger crm. I googled but I could not get the right information. I try to change the menu items and getting the following warnings.

'contacts'=>'customers' in include/language/en_us.lang.php

Warning: Cannot modify header information - headers already sent by (output started at ``vtigercrm/include/language/en_us.lang.php:1) in vtigercrm/index.php on line 606

Warning: Cannot modify header information - headers already sent by (output started at ``/vtigercrm/include/language/en_us.lang.php:1) in vtigercrm/index.php on line 608

Warning: Cannot modify header information - headers already sent by (output started ``at/vtigercrm/include/language/en_us.lang.php:1) in vtigercrm/index.php on line 610

Answer 1

use

ob_start (); and ob_flush();

in your index.php and en_us.lang.php pages the problem will solve.

Answer 2

1- that error states there is a blank line before the opening php statement or 2- you may save en_us.lang.php in utf8 format.
solution:

for 1: remove any extra line(s) before <?php and Also after ?> at the beginning and the end of mentioned file.
for 2: use notepad++ to convert encoding to UTF8 without BOM and then save it.