Fixing "Warning: Cannot modify header information -- headers already sent by.." Error

Great if you are using Wordpress, but what if you are not using Wordpress? Any hack for hand-coded code?

I try it, nop, not working for me, there may be problem in another file, i think

?> is a closing php tag

That seems to have done the trick. Thank you

Yes!!! Like a boss!!! Thanks

hello, i have this error on my website on opencart:
Warning: Cannot modify header information - headers already sent by (output started at /home/linunetg/public_html/catalog/language/ru-ru/ru-ru.php:1) in /home/linunetg/public_html/system/library/response.php on line 36

can you help me? cant find anything.
thank you!

Funny. I couldn't find the ?> there, but I actually tried ADDING it, and it seemed to work! Thanks for telling me where to go!!!

But, I can't even log in to my wordpress dashboard because of that error. Is there another way to login to my wordpress site?

Thank you Thank you Thank you!!! Worked for me :) Youre a gem!

HAAHAHAH THANK YOU SO MUCH. I WENT INTO THAT FUNCTION.PHP TO DO SOMETHING AT THE BOTTOM. I DELETED IT THEN I GUESS I LEFT THE ?> THERE. THANKS SIR

I don't have a ">" only the opening "<?" - what next?

Dear Dan,
I try your solution . But still got error as : Warning: Cannot modify header information - headers already sent by (output started at /home/content/87/12501387/html/index.php:2) in /home/content/87/12501387/html/wp-includes/pluggable.php on line 1179

advise me

Instead of deleting >? i wrote on >? it solved my problem. Fuckkkkkin Awesome trick..
Thanks Buddy

I have literally spent hours and hours researching different ways of fixing this issue. I looked at your video and deleted that stupid ?> and it solved all my problems. WOW

I cannot even find theme functions

This vid might be 3 years old but still works - THANK YOU

Hi Daniel, I follow this but doesn´t works on my website :(

I have a realy Big problem...THAT IS THE CRASY WARNING
Warning: Cannot modify header information - headers already sent by (output started at /homepages/20/d195044051/htdocs/wsb4413378102/wp-config.php:1) in /homepages/20/d195044051/htdocs/wsb4413378102/wp-includes/pluggable.php on line 1196

It doesn't Work x) I delited it x) x)

not for me i'm not using cms

thnx a lottttttttttttttttttt... It worked for me..:)

Thank You Very Much Sirr Its Working Now. Thank You soo much i have been working with this error. Thank You Soo Much Sir

the beeeeeeeeeeeest video .thnk's mennnnn a lot

Hello guys we are having the same problem as you lot are, but we are also unable to even log into our dashboard becuase of this Warning... Warning: Cannot modify header information - headers already sent by (output started at /home1/sltgreen/

Has someone found out how to resolves this problem yet as we cant find no other help anywhere..

It doesn't Work x) I delited it x) x) 

I have a realy Big problem...THAT IS THE CRASY WARNING 
Warning: Cannot modify header information - headers already sent by (output started at /home/hichem/public_html/mastercard/wp-config.php:1) in /home/hichem/public_html/mastercard/wp-login.php on line 424

Warning: Cannot modify header information - headers already sent by (output started at /home/hichem/public_html/mastercard/wp-config.php:1) in /home/hichem/public_html/mastercard/wp-login.php on line 437

Warning: Cannot modify header information - headers already sent by (output started at /home/hichem/public_html/mastercard/wp-config.php:1) in /home/hichem/public_html/mastercard/wp-includes/pluggable.php on line 918

Warning: Cannot modify header information - headers already sent by (output started at /home/hichem/public_html/mastercard/wp-config.php:1) in /home/hichem/public_html/mastercard/wp-includes/pluggable.php on line 919

Warning: Cannot modify header information - headers already sent by (output started at /home/hichem/public_html/mastercard/wp-config.php:1) in /home/hichem/public_html/mastercard/wp-includes/pluggable.php on line 920
MasterCard souktnine

Hello Den .. 
i am using Opencart 2.1.1 i try my level best but i cant fix this some say its editor problem ..
so when i saw this video i search for war you say but in opencart in under in theme there is fo function.php page could you please help me out .. 
Path - public_html/u845747/Demo2/catalog/view/theme/(after this all .tpl file si here )

I deleted it, :/ but a new error occured "Parse error: syntax error, unexpected '<' in /home/i9u4anok/public_html/wp-content/themes/twentyfourteen/functions.php on line 379"

yeah i can't log into my admin as well to even get to that point like Martiene van Steyn just mentioned

It corrupts the file.

I see that message but i cant even log into my back office to delete anything... now its saying cookies...and there is nothing wrong with my cookies...tried to log in on 3 different computers

omg...OMG....OMFG YOU DID IT! YOU FUC*ING DID IT! THX!

Hey Dan, I cant even get to my dashboard... it just gives me several lines of that crappy "cant modify header information" message and no dashboard :-( any ideas?

Hey Dan, I can't access my admin page because every time I click the link from my email that takes normally takes me to the login page, that "cannot modify header information" error comes up. I was trying to see if there was a solution from the other comments below but you didn't have an answer for those who have the same problem as I do. Do you have a fix for this?

Thank you so much man, it worked, love ya!

Just write me here in my inbox or go to my website. Or write me here; dan(at)dangillette(dot)com

how do i email you?

loads of ?> im mine - deleted a few - now getting Parse error: syntax error, unexpected '<' in /websites/123reg/LinuxPackage21/re/ck/le/recklesstimes.co.uk/public_html/recklesstimes/wp-content/themes/pinboard/functions.php on line 218 nightmare..

P.S. I cant access my admin page either.

Dan i have exactly the problem you are referring to. Because I am new to WordPress, i did not understand how to go about solving my problem based upon the video. Can you help me?

I was in a hotel so I couldn't. If you are familiar with wordpress the instructions I give are very simple. If you are not familiar then I guess a video could be helpful. I'll see what I can do then add a link.

This really isn't helpful at all dude.. It would be much more helpful if you made a video of you actually sorting through it step by step instead of talking in to a camera. Just my 2 cents.

I can try. Message me.

Hey Dan, if I give u the URL and my admin panel of domain, anyway you could solve the issue?

I deleted the two <? phrases up at the top of the page as well as the buttom. Then L?php above the word global. Now, I can't even access my wordpress blog without getting the message Parse error: syntax. Please help me out Dan.

Dude! Really? Never delete stuff that can change your whole page without making sure you are deleting the right thing. I was pretty clear in this video. Do you know what you deleted exactly?

You need to delete ?> in the php theme file. You did that?

It says the my <? is the problem | Warning: Cannot modify header information - headers already sent by (output started at /home/u446697960/public_html/gaming/inc/head.php:1) I've tried <?php and that didn't work either T_T

I cant access my admin page so how do i fix it ?