Twig setSourceContext() error

Just a heads up, in case anyone else experiences the same: We were getting this error after a production server reboot (v.7.0.2 Express Plus on AWS):

The most apparent symptom was that patient dashboards would not render at all (all blank under the navbar), while other system functions seemed to work.

The problem went away after another server reboot, so perhaps it is related to launch order of operations.