2.11.9 User Guide

Retired Documentation

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Warning: Cannot modify header information

ExpressionEngine returns the following warning: “Cannot modify header information.”


This error is often caused by blank lines or superfluous white space in a PHP file before the opening or after the closing PHP tag. The offending PHP file is usually named in the PHP error message.

This error can also be triggered by another PHP error, in which case the originating error should be resolved first.