Uncaught TypeError: Cannot read property 'documentElement' of null #1

I just fired up the example provided and got two errors:

Access to XMLHttpRequest at 'file:///GPUEdgeBundling/example/bundling_data/airlines.xml' from origin 'null' has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https.

Uncaught TypeError: Cannot read property 'documentElement' of null

I tried in both Chrome 78.0.3904.97 and Firefox 70.0.1