PrintNode is performing upgrades which will result in temporary downtime. This may prevent remote printing while the scheduled maintenance is occurring. The intention of the maintenance is to "increase PrintNode's capacity, availability and resilience".
What should I do?
1. One workaround is to go to your Settings, click into Printing, then disable the "Bypass printer selection" options on all of your users so they can choose alternative printers not hosted by PrintNode.
2. You can switch everyone to local printers temporarily if they are on mobile devices with wireless printing support or on desktops with connected or networked printers.
3. Google Cloud Print is another cloud print service which is much less reliable than PrintNode going down at least once a month. Google retires this service January 2021 but you can continue to integrate with it in SKULabs up until then.
See
https://www.printnode.com/en/status for more information.