From: DeskNow Knowledge Base
http://www.desknow.com/kb/

java.lang.OutOfMemoryError: Java heap space
http://www.desknow.com/kb/idx/6/165/article/

This error means that there is too little memory being allocated to DeskNow.

Regardless of the amount of memory present in your server, DeskNow will only use a fixed amount.

On large systems, you may need to increase the pre-set amount. See http://www.desknow.com/kb/idx/0/077/article/