Below are the last 100 lines of my website....I have some problems that are causing the Server to crash periodically, I have been informed that the Server Hardware is fine so it has to be a software problem. Im running a dedicated server (linux) interface is Plesk. The main template of my site is Joomla and I have a K2 plugin installed. The site never used to crash but now i crashes everyday.

Can someone please help me find a solution, i'm a amateur and will need spoon feeding, im happy to do this over skype if it would be a in a position to help.

All the best

Martin

[Tue Feb 17 11:44:19 2015] [warn] RSA server certificate CommonName (CN) `THERAPISTNOW.COM' does NOT match server name!?
[Tue Feb 17 11:44:19 2015] [warn] RSA server certificate CommonName (CN) `THERAPISTNOW.COM' does NOT match server name!?
[Tue Feb 17 11:44:26 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$BeforeDisplay in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 26
[Tue Feb 17 11:44:26 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$AfterDisplayTitle in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 59
[Tue Feb 17 11:44:26 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$BeforeDisplayContent in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 65
[Tue Feb 17 11:44:26 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$AfterDisplayContent in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 118
[Tue Feb 17 11:44:26 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$AfterDisplay in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 178
[Tue Feb 17 11:44:27 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/img/ajax-loader.gif, referer: therapistnow.com/
[Tue Feb 17 11:46:02 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/app/img, referer: therapistnow.com/app/video
[Tue Feb 17 11:46:08 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/app/media-gallery, referer: therapistnow.com/app/media-gallery/mediaitem/92-cannabis-real-stories
[Tue Feb 17 11:47:11 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$BeforeDisplay in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 26, referer: therapistnow.com/app/media-gallery/mediaitem/92-cannabis-real-stories
[Tue Feb 17 11:47:11 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$AfterDisplayTitle in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 59, referer: therapistnow.com/app/media-gallery/mediaitem/92-cannabis-real-stories
[Tue Feb 17 11:47:11 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$BeforeDisplayContent in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 65, referer: therapistnow.com/app/media-gallery/mediaitem/92-cannabis-real-stories
[Tue Feb 17 11:47:11 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$AfterDisplayContent in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 118, referer: therapistnow.com/app/media-gallery/mediaitem/92-cannabis-real-stories
[Tue Feb 17 11:47:11 2015] [error] [client 78.111.200.178] PHP Notice: Undefined property: stdClass::$AfterDisplay in /var/www/vhosts/therapistnow.com/httpdocs/app/modules/mod_k2_content/tmpl/Default/default.php on line 178, referer: therapistnow.com/app/media-gallery/mediaitem/92-cannabis-real-stories
[Tue Feb 17 11:47:12 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/app/img, referer: therapistnow.com/app/index.php
[Tue Feb 17 11:48:13 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/app/img, referer: therapistnow.com/app/login
[Tue Feb 17 11:48:20 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/app/img, referer: therapistnow.com/app/therapists-login
[Tue Feb 17 11:48:46 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/app/img, referer: therapistnow.com/app/manager-login
[Tue Feb 17 11:49:24 2015] [error] [client 78.111.200.178] File does not exist: /var/www/vhosts/therapistnow.com/httpdocs/app/img, referer: therapistnow.com/app/therapists-login

Are you using Kan outdated version of K2.
Please backup and update to K2 v. 2.6.9