FIX for : Warning: Cannot modify header information - headers already sent by ..

O.K. as i see many have this problem, the problem may be a result of couple of things but it's most likely that you have translated something and save the file in UTF-8 with signature... To fix the problem just use NOTEPAD2 http://www.flos-freeware.ch/notepad2.html and use Encoding UTF-8 :: save ...

Once again : Do not save your UTF-8 files with signature, use a utf-8 capable text editor like Notepad2 and you will not have problems
Notepad++ and many other editors are messing things up...

I kept getting this error when I switched from English to Spanish (but not back):

Warning: Cannot modify header information - headers already sent by (output started at /store/catalog/language/english/extension/module/information.php:24) in /store/library/language/language.php on line 46

Warning: Cannot modify header information - headers already sent by (output started at /store/catalog/language/english/extension/module/information.php:24) in /store/library/environment/response.php on line 22

I kept coming back to this posted fix. I was using Dreamweaver CS3 to edit, tried notepad too. Turned out that the only way I didn't get the error was when I used the text editor on my server in UTF-8 mode.

This is a great post and helped me a lot. Thank you!

Notepad may not work for all, so don't give up, try another editor in UTF-8, then you won't get this particular error.