Warning: Cannot modify header information

Check admin.php and template-functions.php to ensure that there are no extra spaces before the opening PHP tag <?php and no spaces or returns after the closing PHP tag ?>.

Also, this is a very common issue and a quick search would have yielded you many threads to check for an answer.

As for your second question, it depends on the site design you are using. If it is a “fluid” design, it will “grow” as you change screen size, but a fixed design will stay no matter what setting you use.

Thanks I’ll try that

Thanks NuclearMoose ,
there were a couple of returns after the closing PHP tag ?>.

I got tons of such warnings… I checked the tags but they were ok. No whitespaces, no returns. Could someone help? The complete warning message follows:

Warning: Cannot modify header information – headers already sent by (output started at https://fengliang.3nv.com/.header:2) in /home/vhosts/fengliang.3nv.com/wp-login.php on line 7

Did you check wp-login.php? Don’t check using something like MS Word–use a proper text editor like Notepad++ or equivalent. I have yet to see another cause for this error.

@troubled,
You’re welcome! Glad you got it sorted out. ??

Yes, I used EditPlus.
I searched the web and found a possible cause, that the PHP output buffering option was off. Does it make sense? I know little PHP…
And I noted some difference between my warning and the others: output started at /.header, not a php file. Does that explain something?

I’ve got the same problem as Baby Tux :
“Warning: Cannot modify header information – headers already sent by (output started at https://rigormortis.ni5.com/.header:3) in /home/vhosts/rigormortis.ni5.com/wp-login.php on line 7”

I cheked the whitespaces and returns, it’s OK. Have you got an answer?

Search, and ye shall find: https://tinyurl.com/6ohco

Thank you for your patience, NuclearMoose.
I’d better upgrade my searching skills…