ui-circulation currently depends on react-codemirror2 ^1.0.0 from August, 2017. That release specifically claims not to be compatible with React 16, the version we use. The current major release of react-codemirror2 is 6.0.0, from April 2019. No updates have been made since.

We have two problems here:

1. CodeMirror2 v1.0.0 is way, waaaay out of date

2. CodeMirror2 appears to be unmaintained in general

We should investigate whether updating to v6.0.0 would allow us to shed some other outdated deps, or at least allow us to run with a compatible React version. But we should also investigate whether there is another editor that is being actively maintained.