Hi,
I've migrated my website from one hosting to another and the website management from an agency that has done the website to a freelance. After the migration and the buying of this new account, I've dissociated the agency account and put in the new key. As you can see from the attachment, I've got a problem with the single.php page (but I don't understand the issue) and also, when we like to modify a page that already exists on the website the WordPress theme opens only the Gutenberg editor. My question is: what do I've to do to edit the previous page content without loose the style of the template? Does have the agency to pass to me something of the previous Toolsset account or any template?
Please make sure you use the same theme as before and the screenshot you shared is displays the message as it seems its using default single page template file and it does not added the custom fields. It shows because you do not have standard content template to display the default "page" post type and thats ok. It will not break your site.