Resolve the open_basedir restriction

How to resolve the open_basedir restriction in effect error in WordPress.

WordPress site suddenly started getting this error on administrative pages.
Warning: file_exists(): open_basedir restriction in effect. File(core/post-comments) is not within the allowed path(s): (/data/web/virtuals/269369/virtual) in /data/web/virtuals/269369/virtual/www/domains/mfproductions.cz/wp-includes/blocks.php on line 532
This solution involves modifying the wp-includes/blocks.php file temporarily to bypass the issue.

php
// Original code in wp-includes/blocks.php on line 532
if (is_string( $block_type ) && file_exists( $block_type ) ) {

// Updated code to fix the open_basedir restriction issue
if ($block_type != "core/post-comments" && is_string( $block_type ) && file_exists( $block_type ) ) {

Steps to Apply the Fix:

    Locate the File: Navigate to wp-includes/blocks.php in your WordPress installation.
    Edit the File: Find line 532 and replace:

php
if (is_string( $block_type ) && file_exists( $block_type ) ) {

with:

php
if ($block_type != "core/post-comments" && is_string( $block_type ) && file_exists( $block_type ) ) {

Save Changes: Save and upload the modified file back to your server.
Update WordPress: After applying this fix, update all plugins and WordPress core to ensure compatibility.
Revert Changes: Once everything is updated and working, revert the change in blocks.php for a cleaner setup.