title: You do not have sufficient permissions to access this page
body: <p>I am creating a simple plugin in WordPress. This is a simple form with three fields that will save data to a database table. The plugin is activated successfully, but when I fill the form and press button to submit, it shows me a blank screen with error:</p>
  
  <pre><code>You do not have sufficient permissions to access this page.
  </code></pre>
  
  <p>I searched the Internet but did not find a solution.</p>