Hi I have two problems.
I have installed polylang plugin.
1)When i create a page in a different language(the page exists in the default language) i get this error with 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://www.blu-vet.com
Preview URL: http://www.blu-vet.com/su-di-noi/
2)For example in "About" page(always with Cornerstone) with one element I have the following error:
This element could not render due to invalid template markup. This could be due to changes introduced by a third party plugin. The front end of your site should still function normally
(I need to change it because my website has two languages!)
Thanks for helping me,
I give you backend access in a private comment.