SSL errors - .well-known I am seeing lot of SSL errors after enabling SSL for my site. 
Following is the common error related to the SSL configuration:

AH01797: client denied by server configuration: /var/www/xxxxxx/.well-known


Is this something related to any settings in our Drupal folder like creating ".well-known" folder or adjusting .htaccess settings or is it related to the Apache settings?
That folder is needed by LetsEncrypt and is nothing to do with Drupal. For some details elsewhere on the SO network see https://serverfault.com/questions/796745/letsencrypt-do-i-need-to-keep-well-known-accessible-for-certificate-renewal