Welcome the Technical Support section. Help us in assisting you by providing us with a concise and descriptive elaboration of your issues. Be specific and if possible, provide us with a step-by-step instruction in replicating your problem.
Empty notification mail body when commenting a group activity
When a user comments a group activity (e.g. commenting a message posted on the group wall), notification sent by mail to the user who wrote the message has an empty body.
The following snapshot was done on your demo site. I can confirm that the received mail has an empty content as well (tested on my site).
Can you please update the labels for this topic which is NOT a "Customer Issue" but a "Confirmed bug". I'll then set it as fixed since this is corrected in the latest JomSocial version.