Cannot modify header information

Hello,

When using mysqli authentication on a webpage I get the following message:

Warning: Cannot modify header information - headers already sent by (output started at /home/folder/domains/domain.nl/public_html/cms60/start.php:1) in /home/folder/domains/domain.nl/public_html/cms60/webassist/mysqli/authentication.php on line 206

I have checked the start.php file a couple of times now for blank lines of code specifically on line 1 but found none...
On the very first line of start.php it calls in the mysqli connections include -> No blank lines there
On the second line it includes the authentication.php file -> No blank lines there
On the third line the authentication starts...

///

First 21 lines of start.php
<?php require_once('Connections/cms_i.php'); ?>
<?php require_once('webassist/mysqli/authentication.php'); ?>
<?php
if (($_SERVER["REQUEST_METHOD"] == "POST") && (isset($_SERVER["HTTP_REFERER"]) && strpos(urldecode($_SERVER["HTTP_REFERER"]), urldecode($_SERVER["SERVER_NAME"].$_SERVER["PHP_SELF"])) > 0) && isset($_POST)) {
$Authenticate = new WA_MySQLi_Auth($verbind_i);
$Authenticate->Action = "authenticate";
$Authenticate->Name = "loginCMS60";
$Authenticate->Table = "login";
$Authenticate->addFilter("Log_User", "=", "s", "".((isset($_POST["un"]))?$_POST["un"]:"") ."");
$Authenticate->addFilter("Log_Password", "=", "s", "".((isset($_POST["ww"]))?$_POST["www"]:"") ."");
$Authenticate->storeResult("Log_Id", "sessionId");
$Authenticate->storeResult("Log_User", "sessionUser");
$Authenticate->storeResult("Log_Password", "sessionPassword");
$Authenticate->AutoReturn = true;
$SuccessRedirect = "inside.php";
$FailedRedirect = "start.php?acces=no";
if (function_exists("rel2abs")) $SuccessRedirect = $SuccessRedirect?rel2abs($SuccessRedirect,dirname(__FILE__)):"";
if (function_exists("rel2abs")) $FailedRedirect = $FailedRedirect?rel2abs($FailedRedirect,dirname(__FILE__)):"";
$Authenticate->SuccessRedirect = $SuccessRedirect;
$Authenticate->FailRedirect = $FailedRedirect;
$Authenticate->execute();
}?>

I have also tried to change the order of the first three occurances on the page

Any suggestions on where els to look for the problem?

With Kind regards RV.

Sorry for the delay. The error implies that the connection is throwing an error or has a space in the code.

The error states: "output started at /home/folder/domains/domain.nl/public_html/cms60/start.php:1"

That means that the first line is outputting code to the page and a connection shouldn't be outputting code. Are there any blank lines, spaces, or other code on that line or in the referenced include file from that line? Is the connection information correct and not throwing an error? That is what would be causing this error.

If you give me FTP access I could debug and tell you precisely what the problem is.

Hello Ray,

Thank you very much for your reply... Access details are provided in private message.

Regarding your questions...
I see no white lines or extra spaces and basically the include file is the connections file generated by the mysqli extension...
I have changed the order of includes in a couple of ways... Where it did not throw errors doing this it kept referring to line 1 regardless

Connection information is correct and as soon as I remove everything related to the authentication from the pages behind this one there are no more issues with header already send... Also good to know is that this same cms works just fine on another live server

I hope you can find the cause... Almost hoping it is not just a white space in the wrong place cause then I'll just feel silly

Thank you very much in advance....

WKR

RV

The file itself was corrupted somehow. I've seen this once or twice before.

All I did to fix it was:
1) create a new blank file
2) copy and paste the entire page from the broken page
3) delete the broken page
4) rename the file to the old page name

Technically those steps should result in the exact same file being created, but for some reason it fixes it.

Thank you very much Ray.... Don't think that woud have entered my mind as option to try...
Very glad it wasn't a white space or line though... Again Thank you very much for the support ... wkr rv