I'm developing a custom theme and running into errors. The theme has been tested and working on various servers but, for some reason, since uploading to siteground I get the following error (file paths, vendor name etc. have been redacted and replaced with notes contained inside square brackets).
Warning: Cannot modify header information - headers already sent
"0":"Warning: Cannot modify header information - headers already sent by (output started at /[magento_root_directory]/app/design/frontend/[vendor]/[theme]/registration.php:1) in /[magento_root_directory]/vendor/magento/framework/Stdlib/Cookie/PhpCookieManager.php on line 148","1"
I've read that this is to do with whitespace before the
<?php tag, but there is no whitespace.
registration.php file is as follows (with vendor/theme name redacted):
<?php /** * Copyright © Magento, Inc. All rights reserved. * See COPYING.txt for license details. */ \Magento\Framework\Component\ComponentRegistrar::register( \Magento\Framework\Component\ComponentRegistrar::THEME, 'frontend/[VendorName]/[themename]', __DIR__ );
This is copied exactly from the file. The
<?php tag is on the first line and there is no whitespace following it.
The site is installed on a siteground shared hosting instance, though I don't think this should make a difference.
Does anyone know what the problem is?
There is a massive stacktrace following the error message, which I can share if this information is not enough.
When I visit the website homepage I see a blank page, with nothing logged in the console and the URL reads:
The page reloads, looping indefinitely and creating a new report each time with the same error message.
theme.xml file is as follows:
<!-- /** * Copyright © Magento, Inc. All rights reserved. * See COPYING.txt for license details. */ --> <theme xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Config/etc/theme.xsd"> <title>[ThemeTitle]</title> <parent>Magento/blank</parent> <media> <preview_image>media/preview.jpg</preview_image> </media> </theme>