In the meantime, I looked in the code for trying to find the error.
This seems to be due do the “reset_pass_url” function in wp-content/plugins/maintenance/load/functions.php
filter, which does not return the original value in its first argument which it doesn’t even have.
I modified the file, lines 296 to 303, the following ways and now it seems to work :
function reset_pass_url($arg) {
include_once(ABSPATH . 'wp-admin/includes/plugin.php');
if (is_plugin_active('woocommerce/woocommerce.php')) {
$siteURL = get_option('siteurl');
return "{$siteURL}/wp-login.php?action=lostpassword";
}
return $arg;
}
add_filter( 'lostpassword_url', 'reset_pass_url', 999, 1 );
I added the missing argument and returned it at the end.