Iframe _ plugin

Hi, the following error information appears most of the time while using cornerstone:

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.

Origin URL: http…

I saw the different explanations on the Support, but do not know whom/where/how to change the php file? Do I need to go back to my hosting provider (Alfahosting) in Germany?


Hi Güldem,

Thanks for writing in! First of all, could you please try testing for a plugin conflict by deactivating all of your third party plugins and see if the problem remains. If it’s fixed, you’ll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.

If you’re still having issues, please try to have the PHP memory limit of your site increased.

To do this, please edit your wp-config.php file and insert these lines:

    define( 'WP_MEMORY_LIMIT', '256M' );
    define( 'WP_MAX_MEMORY_LIMIT', '512M' );

You can add it before the line
/*That's all, stop editing! Happy Blogging. */

Here is a details article about the PHP Memory Limit that is in our Knowledge Base (https://theme.co/apex/forum/t/troubleshooting-increasing-php-memory-limit/16935).

Also please go through our knowledge base article on how to troubleshooting builder loading issues (https://theme.co/apex/forum/t/troubleshooting-builder-preview-warnings/14404).

If you’re still having issues, please provide us with your WordPress login credentials in a secure note to check your issue further.

Let us know how it goes.

Hi mldarshana,

I checked with my hosting provider and they asked me, if we really need 512 MB as php memory limit. My current tarif includes max. 256 php memory limit and I would need 2 tarifs upgrate, which causes additional monthly costs and I do not need the services included in the business L tarif.

Currently I do not have any other plugin installed or activitated (except using cornerstone), as I’m just starting to set up my first pages (except using cornerstone).
Can you advice how to find out which plugin might be installed?

How can we proceed?


Hello Güldem,

Thanks for updating the thread.

Can you please share the website login details in secure note? I would like to take a look at the setup. I tried looking at the URL that’s listed in the licence manager but I see Alfahosting page.


Hi Prasant,
thanks for your support. After your reply I could use Agency via cornerstone.
Now, I changed my mind and would like to use the demo content Renew02.
I have now the problem, that Renew02 is not uploading/active, although it presents a positive sign that it is uploaded. I still have Agency as demo content and cannot change it.
How much time does it take, that a new demo is installed?

Hello Güldem,

After the installation of the demo setup is finished on X > Validation it should be available right after. Unless there is an issue that stop the demo from successful installation, you will see such issue. Would you mind sharing credentials inside a secure note so we can see the setup? To see the issue too, if Renew02 failed, would you give us permission to try and install so we can see the issue you were having? Thanks.

Hello Güldem,

Thank you for the credentials.
I am able to login an tried to install Renew02. I can see something goes wrong it goes too fast but nothing happened. There’s no error on console too. Would you mind sharing FTP credentials too so we can check error log? Thanks.

Hey Güldem,

I tested installing Renew 2 and it was imported successfully. The problem is with your web host. You have index.html where you’ve installed WordPress.

I renamed it to index.html.old. Now you can see the Renew 2 demo.

Hope that helps.

Hey Christian,
thank you, I can work now with the Renew02!

You’re always welcome Güldem!


Hi Lely,

the dashboard still presents Agency as demo and not Renew02. Does it any harm, if I update the upload of Renew02?

Thank you!

Hi Güldem,

Actually it does not work that way. If you selected a demo and import it, the demo content will be installed on your site and it is just a one way processed. If you go back to the validation page, the Agency demo is the default selected demo as it is the first choice but that does not matter.

Hope this explains it.

Hi Jade,
Thanks Güldem

You are most welcome. :slight_smile:

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