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This guide applies to:

  • Basic Edition
  • Plus Edition
  • Pro Edition
  • Business Edition

Introduction

Scheduled Event and Cron errors happen when your site doesn’t run its jobs on time. One of the ways this affects your Booking Calendar is when it comes to notifications.

Sending notifications is one of your website’s jobs. So these errors can mean there’s a delay in your notifications sending or they’re not sending at all.

What You Might Be Seeing

  • Delayed notifications
  • “This notification might be delayed or not sent as expected.”
  • “Warning: Scheduled events  
    A scheduled event (ssa_cron_process_async_actions) has failed to run. Your site still works, but this may indicate that notifications and synchronization with 3rd party services may not work as intended.”
  • “A scheduled event (delete_expired_transients) has failed to run” 

Why You’re Seeing Scheduled Event and Cron Errors

WordPress websites by default run and execute code when someone visits a page on your site. This is setup to avoid wasteful processing power.  

When a visitor goes to your home page, WordPress displays the page and also checks for any background tasks that it should be doing (Ex. Sending your Email Notifications).

WP-Cron is the name of the system in charge of checking for jobs. WordPress official guide for the Cron system.

If the system needs to send a customer an email notification at 8AM and no one visits your site until 10AM, that means the email notification doesn’t send until 10AM.

If the appointment is at 9AM, then the notification email won’t send out, and they’ll never get that email. 

Sometimes you’ll receive scheduled event errors, when this happens it just means some of the jobs your website needed to run did not execute on time.  


How to Stop Scheduled Event and Cron Errors

Tracking Emails Sent From Your Site

The first step is to download a free plugin to keep track of the emails that your site sends. We recommend using the WP Mail Logging plugin.

Once you’ve installed and activated your plugin, the plugin will immediately start logging your sent emails. 

To find the log, you’re going to go under WordPress Dashboard > Tools > WP Mail Log. 

Find WP Mail Log Under the WordPress Dashboard Tools Menu
WordPress Dashboard > Tools > WP Mail Log

Before you move on to the next steps, make sure to go back to your calendar and book a test appointment. You could set the email to send to yourself.

Go back to WP Mail log and make sure that all the emails you’re expecting to send out, show up on the log.

If the emails are appearing delayed, or not showing up, it’s a sign that you’ll need Uptime Robot to make sure your WordPress Cron jobs run on time.

WP Mail Logging Log showing the two emails sent from SSA for an appointment.
WP Mail Logging Log showing the two emails sent from SSA for an appointment

Uptime Robot for triggering WP-Cron

There’s a free service called Uptime Robot, that’ll check your website every 5 minutes and trigger WP-Cron. This will make sure your email notifications send out on time. 

Set up a free account with Uptime Robot.

After signing up and logging in, you need to Add New Monitor. 

Add a New Monitor in the Uptime Robot Tool
Adding a new monitor in Uptime Robot

For the settings of the new Uptime Robot Monitor:

  • Set the Monitor Type as HTTP(s).
  • Give the Monitor a Friendly Name, such as the name of your site + Cron.
  • And for the URL use the homepage of your site along with wp-cron.php?doing_wp_cron added to the end.  Example URL for Uptime Robot: https://mywebsite.com/wp-cron.php?doing_wp_cron

You should see the new monitor setup on the left panel, if you click on it it’ll give you more information – like when you started the monitor or if there are any errors with it. 

Once you finish setting up the new monitor, go back to your calendar and book a test appointment to send an email notification to yourself. After booking, go to WP Mail Log and check to see if you see all your expected emails there.  

If they don’t send immediately, wait about 5 minutes to allow Uptime Robot to trigger WP-Cron. If you’re still having trouble with the notifications, see our guide on troubleshooting email delivery issues.

The new monitor editor for Uptime Robot
The new monitor editor for Uptime Robot

Uptime Robot Alternatives

If you find that Uptime Robot is not the best fit for you or if you need more features, there is a variety of other website monitoring systems available. Just make sure the service provides HTTP monitoring or dedicated Cron job monitoring.


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