You don’t have permission to edit this post.
If you see the You don’t have permission to edit this post. error message on GravityView's edit entry page, it means you are using Post Fields on your form, and you are currently logged in with an account that doesn't have Post Editing capabilities.
Whenever you use a Post Field on your form, a WordPress Post will be created during form submission. However, most of the time, the currently logged-in user that is submitting the form on your website has a Subscriber role which doesn't allow them to edit these Posts later, hence the error message.
Only use Post Fields if you truly need their functionality. The most common mistake is using a Post Image field to upload documents on your form. Instead, please use the File Upload field for this job.