I've just installed a new security certificate for my website and changed the configure files as per the faqs and now have a blank website and fatal error admin side. I undid everything but still getting the same messages, I have scoured the forum and have come up blank. Will be grateful for any help!

the messages admin side are...

Warning: main(/home/mysite/public_html/main/includes/functions/compatibility.php) [function.main]: failed to open stream: Permission denied in /home/street/public_html/main/admin/includes/init_includes/init_file_db_names.php on line 32

Warning: main(/home/mysite/public_html/main/includes/functions/compatibility.php) [function.main]: failed to open stream: Permission denied in /home/street/public_html/main/admin/includes/init_includes/init_file_db_names.php on line 32

Fatal error: main() [function.require]: Failed opening required '/home/mysite/public_html/main/includes/functions/compatibility.php' (include_path='.:/usr/php4/lib/php:/usr/local/php4/lib/php') in /home/street/public_html/main/admin/includes/init_includes/init_file_db_names.php on line 32

I have done ssl before so don't understand what went wrong this time!!