If you render your environment and the agents appear to be off the rail it is usually due to changes in the railway infrastructure. Make sure that you reset your renderer anytime the infrastructure changes by calling env_renderer.reset().
When submitting from a Windows system you might run into the following error:
OSError: dlopen() failed to load a library: cairo / cairo-2 / cairo-gobject-2 / cairo.so.2
Please follow the intstruction in the starter-kit to avoid these problems. Make sure to reset your environment.yml correctly.