bridge.msh vs bridge.geo

[cromlyngames]

bridge.py (line 49) loads the geometry from a file called bridge.msh
The repo appears to have that info stored in a file called bridge.geo

bridge.geo does not appear to be called by any of the scripts in the repo

[salazardetroya]

You need to generate the mesh with gmsh. You can open the .geo file with gmsh and generate the mesh there or directly run it from your command line as

gmsh -2 bridge.geo