HTTPS SUPPORT

Guys

I don't know if you are facing this issue, 

whenever I am trying to update my Ubuntu's apache server to HTTPS, my Elgg server crashes....

Did anyone face this. Is there any workaround....

Do I need to change settings inside Elgg....

Also I need to ask, do you have the steps to upgrade the installation of 5.3 to 6.X without deleting the data in the database...Fresh installation is not an option for me....