Ubuntu server upgrade to 14.04.2 lts and ispconfig upgrade to 3.0.5.4p5, websites not working

I have just upgraded my Ubuntu server to 14.04.2 LTS and Ispconfig to 3.0.5.4p5 and now my websites are not working.
I have read other posts and believe that this could be due to the apache upgrade as part of the Ubuntu upgrade.
is it is as simple as adding a .conf to the sites under apache2\sites-available?
Please point this newbie in the right direction, your assistance will be much appreciated.

 

I have somehow managed to get my old websites back up and running without adding a .conf. (not to sure what exactly I did to achieve this)
Problem now is any new website created under isponfig shows the default apache/Ubuntu index.html from www\var\html so not pointing to the right folder.
Help please?

 

Thank you for your response, I am happy with everything that you say here, and I have not renamed any files.
the only thin I am not 100% sure on is how to remove all symlinks, or which ones I should be removing?

 

Hi Till,
I have done all of this but I am still not able to access any new websites that have been created or updated since this.
all I am getting is error 403 forbidden when I try to browse to them.
Any ideas, and sorry for the stupid questions, new at all of this and still trying to learn.

 

I have now managed to get to my web pages displaying the following,
Index of /
Name Last modified Size Description


Apache/2.4.7 (Ubuntu) Server at www.****.**********co.uk Port 80

 

Could this have anything to do with it?
Tue Apr 7 23:45:14 BST 2015 PHP Warning: mysqli::escape_string(): Couldn't fetch db in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 215
Tue Apr 7 23:45:14 BST 2015 PHP Warning: mysqli::escape_string(): Couldn't fetch db in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 215
Tue Apr 7 23:45:14 BST 2015 PHP Warning: mysqli::escape_string(): Couldn't fetch db in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 215
Tue Apr 7 23:45:14 BST 2015 PHP Warning: mysqli::escape_string(): Couldn't fetch db in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 215
Tue Apr 7 23:45:14 BST 2015 PHP Warning: mysqli::escape_string(): Couldn't fetch db in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 215
Tue Apr 7 23:45:14 BST 2015 PHP Warning: mysqli::escape_string(): Couldn't fetch db in /usr/local/ispconfig/server/lib/classes/db_mysql.inc.php on line 215

 

After I update Ubuntu

 

I have reinstalled ispconfig an all seems to now be working again.