How to fix «Unable to apply data patch Magento\Theme\Setup\Patch\Data\RegisterThemes for module Magento_Theme» in Magento ≥ 2.3.5 in Windows?

Replace the line:

with the following one:

if ($url && isset($url['scheme']) && !in_array($url['scheme'], $allowed_schemes) && !file_exists($filename)) {

github.com/magento/magento2/issues/28055#issuecomment-622533641

The same fix solves another problem: How to fix product images in Magento 2.3.5 in Windows?

See also: How do I install Magento 2.4 to Windows?

See also: windows-filesystem tagged topics.

Thank you.