As stated in Defender documentation, Autotasks are piece of code that runs within AWS lambda function within our backend.
Our infrastructure provider has deprecated Node.js 12 runtime and will end support for it. In order to keep Autotasks running and to preserve high security level Defender users would need to manually upgrade Node.js runtime to version 16. Beside upgrading runtime, packed dependencies are going to be upgraded to the latest version.
Upgrade action needs to be run manually for every Autotask by invoking Upgrade from the Autotask menu or from the Notification banner. As there could be breaking changes with newer Runtime and with newer versions of packed dependencies it is wise to check if Autotask runs as before.
On December 14th all Autotasks that haven't been upgraded will be paused and to unpause them users would need to run upgrade action first.