6400X Printing Error Offending Command

I haven't seen this question posed about the WorkCentre 6400x.  I am suddenly receiving the following error messages when printing anything:

ERROR:  undefined    (COMMAND TYPE: name type)

OFFENDING COMMEND: x    "x"

Followed by a string "OPERAND STACK" with 31 entries.  

I am running Mac OSX12 Sierra and have updated to the latest Xerox driver (3.90.0_1788.dmg file).

Any suggestions on what is wrong and how to correct it?

Thanks.