Dialog History Error (Boonex)

When I try to expand the dialog history for a conversation within my Boonex inbox, I get an error message when I select "show":  Warning: DOMDocument::loadXML(): Empty string supplied as input in /home/boonex/public_html/unity/system/classes/BxXslTransform.php5 on line 66. 

This is a huge problem since I have over 200 entries that I need to refer to.

Please help!!

Thanks - Jethro

Please could you provide your account username and password via private message and the message URL to reproduce and fix the problem ?

Please attached image of error. 

The problem has been fixed, thank you for the collaboration.