Error: The preview could not load due to the iframe response being incomplete. This is most often related to a plugin conflict, or customizations introducing a PHP error

[nonagon]

I just updated the Cornerstone plugin on my client’s staging server and received this error, and I’m getting a critical error when pulling up the site in the front end:

The preview could not load due to the iframe response being incomplete. This is most often related to a plugin conflict, or customizations introducing a PHP error.

I found another post on this subject but it didn’t seem to match my situation and it would be helpful if someone from theme.co could login to the staging instance of WP admin and take a look at this issue.

[tristup]

Hi Matt,

Thanks for reaching out.
I have checked and found that you are still using the older version of X, whereas updated the Cornerstone to its latest. The issue you are having might be due to the incompatibility between the X and Cornerstone versions. I would suggest you follow the below steps while updating the X theme and the Cornerstone.

1. Delete the existing Cornerstone
2. Update the X theme to the latest version on automatic updates
3. After the X theme is updated, use the link in the dashboard to automatically install the Cornerstone. It will be in the latest version.

If that does not help, there might be some different reasons behind your issue. I would like to suggest troubleshooting the following common issue to help us to recognize the reason.

1. Theme Related Issue
2. Plugin Conflict
3. Theme Update related issue
4. Child Theme Related issue
5. CSS/JS Customization
6. Disabling Cache
7. Disabling CDN

If you discover that an issue is coming from a custom code or 3rd party plugin, kindly consult with a developer or contact the plugin author. Please note that we do not provide support for custom codes and 3rd party plugins.
If none of the above help, please copy your live site to a staging server so we could troubleshoot freely without breaking your live site.
And give us access to the secure note including:

– WordPress Site URL & Login URL
– WordPress Admin username/password

To create a secure note, click the key icon underneath any of your posts.

Thanks

[nonagon]

This worked! Only issue is that the homepage will not load in the new Cornerstone editor (I only see the loading bars). All other pages seems to work. Any ideas?

Also, WordPress admins should be advised to NOT update Cornerstone (even when it says Update Available) from the plugins area, as it broke my site.

[nonagon]

I was able to solve the homepage issue by duplicating the homepage and setting the duplicate as the front page. But now some pages will still not load in Cornerstone, even after duplicating…it’s seemingly arbitrary. Another issue I’m now encountering is adding page sections using saved section templates no longer functions - I only see the loading bars and the section is not added.

.

[tristup]

Hi Matt,

I have checked it again by creating a new page and adding the saved Section and it worked perfectly fine. If you are still facing the same issue, I would suggest you check once by clearing all types of cache and check in the incognito/private mode of the browser.

Hope it helps.
Thanks

[alejosbrand]

Can someone please login to my account to resolve this please?

[alejosbrand]

Problem solved it was a plugin i wasnt using!

[prakash_s]

Hello @alejosbrand,

Glad that you were able to find out the plugin conflict and fixed your issue by yourself. Please feel free to open a new thread if you have any more concerns.

Thanks