During routine operation of our POS system, our Odoo service crashed with a 'ModuleNotFoundError: No module named babel' report. The strange thing is, nobody had made any changes to the server and the POS was being used as normal. Restarting the Odoo service got everything up and running again without us having to reinstall babel which leads me to think that something happened during normal operation to stop the babel process but I'm completely at a loss for how this might have happened. Any ideas what could have caused this?

We are using Odoo 12.0 community running on an Ubuntu 18.04.3 LTS server.