It should not have happened, but it happened. I moved my database to a new MySQL server and I was not able to create new posts. WordPress was showing a error saying “This site has a critical error. Please check the email”.
I was also not getting email because of some issue. So to find the exact cause, I used the plugin ‘Error Log Monitor‘ and it listed errors on Dashboard.
The above error could be fixed by enabling the ‘Auto_Increment’ for ‘Id’ field of the wp_posts column.
Cheers and Peace out!!!