CsmapReprojector fails with vertical datum (3D reprojection)

Hi,

I have two raster files, DEM_epsg25831_orthoHeights.tif and GEOID_epsg4326.tif, and I have to convert from orthometric heights of raster DEM to ellipsoidal ones. I am using CsmapReprojector [3] with FME Workbench 2019.1 but I have problems with vertical adjustment.

I always get this error:

CsmapReprojector: Reproject: Could not reproject the geometry of the preceding feature: 

Program Terminating

Translation FAILED.

These are the steps that I follow for vertical adjustment:

1) I have converted DEM_epsg25831_orthoHeights.tif into dtm_epsg25831_orto.asc (Esri Ascii GRID), because CsmapReprojector can only reproject raster files in 2D (that is, with Ignore heights and leave them unchanged) [1].

This is the content of dtm_epsg25831_orto.asc (sample data for test),

NCOLS          3

NROWS          3

XLLCENTER    398955.000000000

YLLCENTER    4624395.00000000

CELLSIZE    5.00000000000000

NODATA_VALUE    -9999

252.71 252.38 251.94

252.97 252.63 252.26

253.23 252.89 252.55

2) I also, I have converted GEOID_epsg4326.tif to EGM96 GRD format using convert-ngrid-to-grd.fmw [2].

3) F‌inally, I have created a .gdc file and I have copied binary ._96 file with .grd file [2, Update note]

I have tried CsmapReprojector with 2D reprojection (epsg2581 -> epsg4326) and works perfect, the problem is with vertical adjustment.

I am wondering if there is something else I'm forgetting to do?

Thank you

[1] http://docs.safe.com/fme/html/FME_Desktop_Documentation/FME_Transformers/Transformers/csmapreprojector.htm

[2] https://community.safe.com/s/article/creating-vertical-adjustment-grid-files-for-use-wi

[3] https://community.safe.com/s/article/which-transformer-do-i-use-to-do-3d-reprojection-v