Drupal: Error Message when add new page

Question

I have new Drupal. I am not sure about Drupal work with add page, article or blog.

This error shows when I add new page click on "preview" button then click "save" button or click on delete link.

Here error message

"The content on this page has either been modified by another user, or you have already submitted modifications using this form. As a result, your changes cannot be saved."

Why Drupal not allow Save content after I preview?

Please kindly help with this problem.

Thanks

Answer 1

This message is caused when either (1) two users access the edit page and one user saves changes before the other user gets a chance or (2) when a user edits content, saves it, and clicks the back button to get back to the edit page.

Solution: From Home » Administration » Configuration » Development click on Clear all caches button.