Hi Motibon,

Thanks for reaching out. These types of error occur on 404 pages, search results pages, or custom templates that don’t have a post context. It indicates that the theme is attempting to access a post_type property when the $post object is not set or is null. This often happens when the website code is trying to run outside the main WordPress loop (e.g., in headers, footers, or certain custom templates), where the $post variable is not defined.

Can you give us more details on the error, like what theme are you using?  And, has the theme ever worked correctly or is this your first time setting it up? If the theme has been functioning properly until recently has anything changed on the site (Updates, Adding/Removing plugins etc)?

Thanks, we look forward to assisting you with this!