"iFrame Response Being Incomplete"Page Builder Error

[rvantricht]

We’re getting the “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.” error on a select few pages when trying to bring up the builder. We previously used the builder to build out these pages, but as of late we’re getting the issue. We’ve also tried duplicating the pages - those duplicates give us the error - and we’ve tried creating new pages from scratch and using the same slugs as the pages with the errors (those old errored pages are then deleted), but we still receive the same error. We don’t have any redirects associated with these errored pages.

We’ve tried all possible solutions relating to this error shown on https://theme.co/docs/warnings-in-the-builders#other-errors, to no avail. The wp_debug outputs the same issues as it does with pages that we can load up successfully in the builder, so there’s nothing there to let us know what the issue is.

What else can we try to get these pages back up to being editable?

[ruenel]

Hello @rvantricht,

Thanks for writing in! Have you inserted a custom html codes on the page? Please make sure that your code is valid and correct. To better assist you with your issue, kindly provide us access to your site so that we can check your settings. Please create a secure note with the following info:
– Link to your site
– WordPress Admin username / password
​
To know how to create a secure note, please check this out: https://theme.co/apex/forum/t/how-to-get-support/288

Regards.

[rvantricht]

No - no custom HTML has been added to the page. The pages all consist of elements with no custom coding. I’ll attach the login and the errored pages in the note.

[christian]

Hey @rvantricht,

It looks like there’s another system is taking over those pages from being edited by Pro. I understand that you don’t have redirects but the Content Builder won’t have any problems if nothing there’s no problem with the URL. Please make sure there’s no redirect in your site by resetting your htaccess file. See https://www.tipsandtricks-hq.com/how-to-reset-the-htaccess-file-of-your-wordpress-site-using-ftp-8527

It’s not the content causing the issue because I’ve saved it as a template and loaded it to a test page (see secure note) and the builder is working.

Please also clear the cache of your caching plugin and deactivate it while we’re investigating.

Thanks.

[rvantricht]

Hey @christian,

I’ve just cleared out the htaccess file, but had to re-save my permalinks settings as all of the pages on our staging site were then pointing to our live site.

I then renamed the slug of one of the errored pages to a slug we’re not going to use, and created a brand-new page that hasn’t been touched by any other system, and renamed that page’s slug to the same slug as the old page. Tried to open that brand-new page in the Pro builder and am still getting the same error.

I just double-checked our redirect plugin (which is built into our SEO), and there’s no redirect entry containing anything remotely close to the slug that I just renamed the brand-new page to. Checked the new htaccess file as well after the permalink settings save and it only contains the code from the link that you sent.

Per your request, I’ve just cleared the cache of our site and disabled the caching plugin.

[christian]

Hey @rvantricht,

It’s one of the third-party plugin causing the issue. I’ve deactivated all of them and pages work in the builder.

Please activate the plugins one by one while checking if the issue will return each time.

Hope that helps.