BugWP logo BugWP
Back to Community
Home / Community / Plugin → Wp crontrol

Troubleshooting Common WP Crontrol Errors: From Fatal Issues to Warning Messages

34 threads Sep 16, 2025 Plugin → Wp crontrol

Content

WP Crontrol is a powerful tool for managing WordPress cron events, but like any complex plugin, it can sometimes throw confusing errors. Based on community reports, we've compiled a guide to the most frequent issues and how to resolve them.

1. Fatal Errors: "Cannot access offset of type string on string" & "Uncaught TypeError"

The Problem: These critical PHP errors (E_ERROR) often occur when trying to create or modify a cron event or schedule. They typically point to a type mismatch, where the code expects one data type (like an array) but receives another (like a string or integer).

Why it Happens: This is frequently caused by incorrect data being passed from another plugin or theme that has improperly defined a custom cron schedule. The data structure WP Crontrol expects does not match what it receives.

Solution:

  1. Navigate to Tools → Cron Schedules in your WordPress admin. Look for any schedules that might have a non-numeric interval or seem incorrectly configured.
  2. Deactivate all other plugins and switch to a default theme (like Twenty Twenty-Four). If the error stops, reactivate your plugins one by one to identify the conflict.
  3. Ensure any custom code that adds cron schedules uses a numeric value for the 'interval' argument.

2. PHP Warnings: "date() expects parameter 2 to be integer, string given"

The Problem: These non-fatal warnings clog up error logs and often appear on the WP Crontrol admin pages. They are related to an invalid timestamp.

Why it Happens: The WordPress cron system (wp_options table) contains a corrupted cron event with a timestamp that is not a valid integer. This is a long-standing issue that newer versions of PHP report more aggressively.

Solution: This often requires directly fixing the data in the database. Always back up your database first.

  1. Use a database tool like phpMyAdmin to access your WordPress database.
  2. Find the wp_options table and locate the row where option_name = 'cron'.
  3. Examine the serialized data in the option_value field for any obvious corruption. A tool like unserialize.com can help you decode it. Look for timestamp keys that are not integers.
  4. If you find corruption, you may need to delete the cron option. WordPress will regenerate it, but you will lose all scheduled events and may need to reconfigure them.

3. Cron Event Failures: "The cron event list could not be saved"

The Problem: You see errors stating that a cron event could not be rescheduled, unscheduled, or saved.

Why it Happens: This is almost never a problem with WP Crontrol itself. This error means WordPress core's wp_cron system failed to save the list of events back to the database. This can be caused by:

  • Object Caching: Aggressive persistent object caching (e.g., Redis, Memcached) can interfere with the transients used to manage cron events.
  • Database Issues: Table corruption or permissions problems on the wp_options table.
  • Conflicts: Another plugin hooking deeply into the cron system.

Solution:

  1. Temporarily disable any object caching solutions or their WordPress drop-in (e.g., object-cache.php).
  2. Check for and repair any database corruption.
  3. Check for stuck or duplicate cron events in the WP Crontrol list and delete them.

4. Errors from eval()'d Code

The Problem: Errors that mention eval()'d code on a line related to wp-crontrol.php.

Why it Happens: This is a common point of confusion. WP Crontrol allows you to create cron events that run raw PHP code. These errors are not from the WP Crontrol plugin code. They are syntax or fatal errors from the custom PHP code that a user has entered into a PHP cron event.

Solution: Review all PHP cron events you have created. The error message will indicate which line in your custom code is causing the problem (e.g., eval()'d code on line 1). Fix the syntax error in your custom PHP script.

5. "Failed to schedule the cron event"

The Problem: You try to run or schedule an event manually and get a generic failure message.

Why it Happens: The specific hook (e.g., akismet_scheduled_delete) may have validation logic that prevents it from being run outside of its intended context. It can also be a symptom of a deeper conflict or a caching issue.

Solution: This is usually an issue with the plugin that owns the hook (like Akismet), not WP Crontrol. However, you can try:

  1. Deactivating and reactivating the plugin that the cron event belongs to.
  2. Checking for duplicate or stuck events and deleting them, which can sometimes resolve the conflict.

General Troubleshooting Steps

For any issue with WP Crontrol, always start with these steps:

  1. Conflict Test: Deactivate all plugins except WP Crontrol and switch to a default theme. If the problem resolves, reactivate your software one by one to find the culprit.
  2. Check for Stuck Events: Look through your list of cron events for any duplicates or events that appear to be failing repeatedly. Deleting them can often clear up issues.
  3. Review Custom Code: If you use PHP cron events, validate your code in a local development environment first. A small syntax error can cause a fatal error on your live site.

Remember, WP Crontrol is primarily an interface for managing the WordPress cron system. Many errors it displays are actually symptoms of problems elsewhere—in other plugins, themes, custom code, or the database. Isolating the cause is the key to finding a solution.

Related Support Threads Support