Debugging OptinMonster

Occasionally you may come across some issue with OptinMonster. The most likely scenario is that there is a conflict with your theme or plugin, and the solution is a relatively easy one to fix. We have answered thousands of tickets, and these are the most common bug scenarios we have found and fixed. Please review the following items below before submitting a support ticket as the solution to your issue may already exist!

Quick Tip: Use Cmd + F (or Ctrl + F on a PC) to do a quick search for a term that may help you locate your bug and possible fix.

Getting Started

First things first. When debugging OptinMonster, we would highly recommend using Google Chrome. They have a very helpful debugging tool that lets you know exactly where errors are occurring and the nature of them. When in Google Chrome, do the following:

  1. Visit the webpage where the error is occurring.
  2. Right click on the page and select the “Inspect Element” option from the screen popup.
  3. Once the debugging window has appeared, click on the “Console” tab to the right.

If there are any JavaScript errors on the page, they will be listed in this console area. The messages output can be very beneficial for debugging OptinMonster.

Possible Issues and Fixes

Campaign Not Loading

The following are the most common reasons a campaign fails to load as expected:

  • Campaign Not Embedded: The campaign embed code has not yet been added to the site (non-WordPress), or the Output Settings haven’t been configured (WordPress). See our documentation for instructions on adding OptinMonster to your specific site’s platform.
  • Invalid or Incorrect Display Rules: The Display Rules for the campaign are invalid or preventing the campaign from loading on the specific page. Double-check the Display Rules set for your campaign according to our page level targeting documentation.
  • Incorrect Domain: The domain set for the campaign to load on may contain a typo, or not match the front-end domain for your website. Some websites will use one domain for the admin of their site and a different domain for the front-end. If your site is configured in this way be sure you’ve added both domains for your campaign to load on.
  • Javascript Errors: Javascript errors on your site can interfere with OptinMonster. You can use Chrome’s Dev Tools to check for Javascript errors on your site.
  • jQuery Library Issue: In some instances a website will load multiple copies of the jQuery library, this can become an issue if the site also loads different versions of the jQuery library. If you are running legacy campaigns, OptinMonster will check for and load version 1.12.2 of the jQuery library if your site isn’t already loading it; unless you specifically need a different version of jQuery loading on your site you should load only a single instance of version 1.12.2. You can migrate your legacy campaigns to 5.0 versions and OptinMonster will no longer load jQuery to run the campaigns.
    Alternatively, in some cases, you may wish to load a different version of jQuery on your site that is still compatible with legacy OptinMonster campaigns (jQuery 1.11.x and greater) and disable OptinMonster from automatically loading jQuery 1.12.2. This can be done by adding the following javascript to the footer of your site:

Campaign Not Loading on Specified Display Rules

It’s possible there is an error in the configuration of your Display Rules, preventing the campaign from loading as you expect across your site. Be sure to review our page targeting documentation for a full walk-through of the process.

If you’re still having difficulties, submit a support ticket and we’d be happy to assist you!

Merge Field Error

If you’re using MailChimp and receiving the following error, there are two possible causes/resolutions:

Oops! It looks like there was an error: There was an error with your submission: Your merge fields were invalid


This error occurs when:

  • Your MailChimp’s List settings require a certain field, such as the First Name input field, but you’re not displaying the First Name field in your campaign;
  • or, the First Name input field has a name other than FNAME in your MailChimp account’s settings.

To correct this issue, login to your MailChimp account and navigate to Lists > Your List and from the Settings dropdown select the List fields and *|MERGE|* tags link.


Locate your required field (such as the First Name field) and disable the required option if you aren’t displaying the First Name field.


Be sure to Save Changes and your form should be ready to submit!

Campaign Image Displaying Too Large

OptinMonster does not crop or resize your image(s) on upload, and the original image size is added to the campaign. In some browsers, if the image is larger than the intended space it can result in the campaign’s content becoming distorted to accommodate the image.

We recommend you resize the image using your favorite image editor and re-upload it to correct this issue. Not only does this resolve the appearance, it will improve the campaign’s pagespeed performance for your visitors.

See how to optimize your campaign images for a quick list of all template image sizes for easy reference.

WordPress-Specific Debugging:

I have downloaded the OptinMonster WordPress plugin .zip file but it’s appearing as a folder in my Downloads. What do I do?

All you need to do is re-zip the folder so that you can then follow the installation instructions for installing OptinMonster. Your browser is probably set to unzip a file upon download. You can re-compress the OptinMonster file yourself (so it is zipped) and upload it to WordPress, install OptinMonster from your Plugins > Add New screen, or you can manually upload it using FTP.

Helpful Documentation:

How do I get updates for the OptinMonster WordPress plugin?

Go to Dashboard > Updates. Any updates will be listed here.

If you do not see any updates for OptinMonster but have been informed that there are some, you may need to refresh the page a time or two to see the update that is available.

My campaigns aren’t showing in the WordPress admin.

If you’ve created at least one campaign, but the OptinMonster plugin isn’t showing it available, be sure to check that your campaign is set to load on your site’s domain.


Only campaigns set to load on your site will appear in the WordPress > OptinMonster > Campaigns tab.

Publish Website

I’ve enabled my campaign, but it’s not loading on the front-end.

There are a couple of reasons your campaign may not be properly appearing on the front-end, including:

  • The Site URL your campaign is set to appear on is incorrectly formatted. Be sure the domain you entered does not contain a trailing slash, or if it does add a new site with the correctly formatted domain, delete the incorrect one and update your campaigns to reflect this change.
  • Page Level Targeting hasn’t been set, or has been improperly set. When using WordPress you don’t need to Page Target using the campaign Builder so that section can be left blank. Instead, you control the appearance of the campaign on your site through the OptinMonster Plugin settings. Please review our documentation on page level targeting, scrolling down to the section addressing WordPress, before submitting a support ticket.
  • You’re using a JavaScript minification plugin, such as W3 Total Cache, Autoptimize, BWP Minify, etc. JavaScript minification plugins can prevent OptinMonster from functioning properly. Some minify plugins allows you to exclude specific JavaScript files, be sure to check that the minify plugin you’re using also allows you to exclude specific JavaScript files. You’ll need to exclude OptinMonster’s api.js file from being minified.
    If you’re using Autoptimize just add api.js to the “Exclude scripts from Autoptimize” field and save.