I tried to reproduce the study area, but the problem of this crashed me.
MT3DMS - Modular 3-D Multi-Species Transport Model [Version 5.30]
Developed at University of Alabama for U.S. Department of Defense
Using NAME File: mt.nam
The value of the STATUS specifier in an OPEN statement does not match the file status (unit=10).
Error occurs at or near line 163 of _btn5open_
Called from or near line 169 of _MAIN__
The 'Flow Direction' can successfully appear, but the MT3DMS doesn't work as wished.https://i.stack.imgur.com/E9zug.png