Php：警告：标题可能不包含多个标题，检测到新行

its unbeliveable. This is all I got, at the very first file which is executed:

header ("Pragma: public
Expires: 0");die;

and the error? Warning: Header may not contain more than a single header, new line detected in ... WTF? I var_dump()-ed the included files, but it contain this file only.

What is unclear about the error?

You have a new line here:

You are trying to set two headers. You need two header() statements instead of one with a line break in the string.

header("Pragma: public");
header("Expires: 0");
die();