when i select Let's Encrypt SSL option for a web site the mark is cleared after i refresh the web page and the selected web paged dont run in https please advice how to check my server config for missing options or something that i didnt installed
Your SSL LE cert could not be issued. Check your logs. The reason is that website cannot be validated probably. The usual reason is that website is not pointed to your server in DNS zone.
Please try to use the search function first, there are so many threads in the forum about Let's encrypt topics and almost all point you to the FAQ: https://www.howtoforge.com/community/threads/lets-encrypt-error-faq.74179/