When you use the Letter Writing Assistant (LWA) to 'Prepare an Employee benefits and deduction letter' and select the 'Benefit Summary (For Payroll) or Open Enrollment Notification (For Payroll) letter template options, GP appears to hang, and/or you receive the "Invalid Merge Field" message box, and the letter in Microsoft Word will display the following error in these fields:
"Error! MergeField was not found in header record of data source"