I was building a demo where I was wanting to show the document information panel in Word 2007 (which I think is one of the neatest features about it!) . It should look like:
But instead I was getting “The document information panel was unable to load“.
I couldn’t see a reason for this, but investigation found this post which shows the same error, and a solution in the comments:
The System Event Nofication Service (SENS) uses the same communication “channels” (not the correct word, but works) as does office products do in communicating with the server.
Stop and disable the SENS service on the server and everything will work perfectly.
So, open a command prompt and type:
net stop sens
Bit strange, but that fixed it for me. Also note the comment at the bottom that the Document Conversions service doesn’t work on a single server demo system like this.
Andy Burns' Blog 
Thanks a LOT man !!! 😀
ditto 🙂
There wasn’t much on Google that I could find, so I decided to blog my fix. Here is the issue, in Microsoft Word 2007 I would click on the office button –> Prepare –> Properties in order to see metadata and instead of seeing the metadata I got the following message “The Document Information Panel was unable to load.” It turns out that Word uses an InfoPath DLL to make this function work. The name of the DLL is IPEDINTL.DLL. In my case the DLL was missing hence the error message. After replacing the DLL, it functioned just fine. For some reason some of the “%systemDrive%Microsoft Officeoffice121033” file folder was installed in another location.
See the full solution at:
http://freewarecritic.blogspot.com/2008/07/document-information-panel-was-unable.html
Top tip mate – many thanks…
Love a command line fix!!
Thanks alot,
I had the same error message. it turned out that InfoPath was not installed. I installed that the Document Information Pannel displayed.
Still the same mates..even after doing above also i am getting the same error
Happens when you install Office on the SharePoint server.
http://blogs.rjbtech.com/RW/archive/2010/08/26/the-document-information-panel-was-unable-to-load.aspx
try this
http://allyoucanimagine-haskar.blogspot.com/2012/04/enable-information-panel-for-custom_17.html