From >>>This AKN<<<:
"Select the grid files required for this transformation.
Click + to browse to grid files on your system. AutoCAD Map 3D toolset does not check whether your grid file is in the selected format. You must ensure that the format and the grid file match."
OK, so how do you determine what format a GSB file is in?
Dave
Dave Stoll
Las Vegas, Nevada
64GB DDR4 2400MHz ECC SoDIMM / 1TB SSD
NVIDIA Quadro P5000 16GB
Windows 10 Pro 64 / Civil 3D 2024