---
title: "Critical Error: WP_Background_Process Not Found"
description: "If Wishlist for WooCommerce causes a fatal error saying Class \"WP_Background_Process\" not found, rename the wish-list-for-woocommerce plugin folder via FTP or your file manager to restore admin access. Then re-download the plugin ZIP from WordPress.org, re-upload it, check for plugin…"
url: "https://wpfactory.com/docs/wp-background-process-not-found/"
updated: "2026-09-26"
category: Troubleshooting
tags:
  - Wishlist for WooCommerce
---

# Critical Error: WP_Background_Process Not Found

If Wishlist for WooCommerce causes a fatal error saying Class "WP_Background_Process" not found, rename the wish-list-for-woocommerce plugin folder via FTP or your file manager to restore admin access. Then re-download the plugin ZIP from WordPress.org, re-upload it, check for plugin or theme conflicts, and confirm your PHP version is supported.

## **Problem Description**

After installing or updating the Wishlist plugin, the admin area (or site) breaks. WP shows a fatal error like Uncaught Error: Class "WP_Background_Process" not found, preventing access to plugin settings, plugin list, or sometimes the entire admin dashboard.

**Common symptoms**

- White screen or “Critical error on this website” message in WP admin.
- Error trace referencing: includes/free/class-alg-wc-wish-list-stock-bkg-process.php and “WP_Background_Process”.

**Cause**

- The plugin tries to load a background‑process class that’s missing — likely due to incomplete file deployment or conflict with another plugin/theme that interferes with autoloading.

**Solution (step‑by‑step)**

1. **Temporarily disable the plugin** — via FTP or hosting file manager, rename the plugin folder wish-list-for-woocommerce to something like wish-list-for-woocommerce-disabled. This restores access to WP admin.
2. **Ensure plugin is fully uploaded / no missing files** — re-download the plugin ZIP from WordPress.org and re-upload via WP Admin → Plugins → Add New → Upload. This ensures all files (including background‑process classes) are present.
3. **Check for conflicts:** disable other plugins or custom code that modify autoloaders or background processes; switch to a default theme. Then reactivate the wishlist plugin and test.
4. **Verify PHP version:** make sure your server uses a PHP version supported by the plugin (per plugin page requirements).
5. **If error persists, contact support:** Provide the full error message, WordPress version, PHP version, theme name, and list of active plugins, this helps developers debug missing file / dependency issues.

**Prerequisites**

- FTP or hosting access to rename/delete plugin folder.
- Backup of site before making changes.

**Additional Notes**

- This issue seems rare but critical, treat it as high-priority if it arises.
- Always test plugin updates on a staging site before applying to production.

**Related Issues / Alternative Solutions**

- Consider waiting for a patched release if this is due to a plugin bug, check changelog.
- If background processing isn’t essential for your store (e.g. stock alerts), consider disabling related features temporarily for stability.

Related articles

- [Wishlist Page Returns 404 Error](https://wpfactory.com/docs/wishlist-page-returns-404-error/)
- [Wishlist Issues with WPML and Multiple Languages](https://wpfactory.com/docs/wpml-wishlist-issues/)
- [“Add to Wishlist” Also Triggers “Add to Cart”](https://wpfactory.com/docs/add-to-wishlist-adds-to-cart/)
- [“Remove from Wishlist” Not Working on My Account](https://wpfactory.com/docs/remove-from-wishlist-not-working/)
- [Multiple Wishlists Not Working: Missing Items, Notes or Quantities](https://wpfactory.com/docs/wishlist-issue-pro/)

 

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