Thank you for sharing admin access details but when I try to login using the latest admin access details shared with the previous reply - it asks for (2FA) verification code.
Can you please disable the (2FA) verification so that I can login to the site.
I told you some messages ago that the page is in the frontend available but I get no access to this content-template and some others in the backend, I always get the message of a critical failure.
But that does not mention with what content template you have issue with? I'll require exact information with what content template you have issue with and you get error with.
I've search in the postmeta table for the post_id equal to content template ID.
For example:
SELECT * FROM `wp_4_3_postmeta` WHERE `post_id` = '1758'
And then with the result I found I've deleted the row with post meta key equal to 'tb_preview_post' that holds the post ID (which is the post ID of post that is actually deleted and that is why you get that error).
Happy to inform you that now its fixed and you are welcome to close this ticket.