NameError: name 'null' is not defined

[HetCatChem91]

Hi! When running the catmap tutorial, I'm running into the following error when executing the reaction model. I do not see 'null' appearing in the code as I understand this will need to be replaced by 'none'. Any guidance would be much welcome - thanks!

[ajmedford]

I would first try checking the versions of Python and all necessary packages. The build is passing, and the tests are the tutorials, so if all the versions are correct then the tutorials should run. You can check the yaml file for the continuous integration for more details on the setup used for the testing if needed (I believe it is tested with Python 2.7 and 3.6 with miniconda).

https://github.com/SUNCAT-Center/catmap/blob/master/.travis.yml