Error #5922 indicates a communication error between GIFTS and Microsoft Word, and may be caused by a number of different issues. If this error occurs when using a specific correspondence template, it may indicate that the link between the template and its merge file (.MRG file) has been broken.  

To fix this error - try recreating the headers in the template. To do so:

-Launch Administrator > Setup > Correspondence Templates
-Select a template
-Click Action (in toolbar) and then recreate headers