Body of email is missing in Outlook

Symptom:
The AVG or NOD32 or GDATA add-in deletes the message body.

Solution:
To remove an add-in:

Outlook 2007: Tools > Trust Center > Add-ins
Outlook 2010/2013/2016: File > Options > Add-ins

In the Manage field choose COM add-ins and click Go
Highlight an add-in and click Remove

Source:
intermedia.net