Problem running real.exe with FDDA

Good afternoon all, I am attempting to run WRF with FDDA. I have completed obsgrid successfully and am attempting to run real.exe, but I am getting the following error:
taskid: 0 hostname: ncaqc2017
module_io_quilt_old.F 2931 T
------ ERROR while reading namelist fdda ------
Maybe here?: &fdda
Maybe here?: grid_fdda (max_dom) = 1 ; grid-nudging fdda on (=0 off) for each domain
-------------- FATAL CALLED ---------------
FATAL CALLED FROM FILE: <stdin> LINE: 11077
ERRORS while reading one or more namelists from namelist.input.
-------------------------------------------
[unset]: aborting job:
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0

How do I resolve?

Thank you,

Elliot Tardif

Which version of WRF are you running? Please upload your namelist.input for me to take a look.