What does this PHP error message mean and what could be causing it?

Question

On one of my pages i get this error:

Ive heard it could be to do with 'white spaces' but have checked and not found any. Is there anything else that could be causing this?

Also what exactly is a white space, is it just a gap in the script?

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/content/t/n/i/tnine/html/Main/md.php:6) in /home/content/t/n/i/tnine/html/Main/md.php on line 51

Thanx.

Answer 1

This error is caused because you have already send something to the browser and are now sending the headers.

Let me explain, session_start() sends some headers to the browser, and as a thumb rule all the headers must be send in before you start sending actual content to the browser(makes sense also, as headers tells the browser how to treat the information coming in).

So, just look out for any HTML code or echo statements in your code that are being executed before this session_start() function, Just try bringing them down, i.e. after this statement(or any other function that may be sending headers).

Answer 2

That particular error could be caused by any number of things.
White spaces are spaces left in code you cannot see, most common in Metabapd (c).
It may be caused by white spaces or a syntax error. Visit the site below for more information

Answer 3

Sometimes Windoz can't handle all the programs you have up and crashes. A quick fix is to reboot you pc, but doesn't fix the underlying issues. Try to clean up your pc. You may have programs running that you don't know are running, which you don't need or want running. Check your startup group for items you don't want or need running in the background. If you have installed and uninstall several programs, your registry may be messed up. There are programs to fix registrys. Bottom Line: You need to clean up your pc of surplus programs and malware and then defrag the HD. Windoz is a high maintenance OS, so you need to clean it up regularly. If you don't know how, research, ask.

Answer 4

The other answers have suggested looking for echo statements & whatnot. Another thing to look for is a blank line after the closing ?> tag in a file you include/require. The editor in cpanel's file manager loves to add these.