java.lang.IllegalStateException: session.command.page.cap?Png, 100, viewPort, true) must not be null

[molly-looker]

We see this error in rendering large visualizations in a docker container that has not properly set up memory: https://bugs.chromium.org/p/chromium/issues/detail?id=715363

You can fix it by modifying the shm size by passing the optional parameter --shm-size to docker run command. The default is 64MB and you will want to increase this to potentially 128 MB. Since you are not using this memory unless needed, you could also increase it to 256MB.