The 11.x platform uses a Kafka-based databus to connect the ESM to devices such as a receiver. Earlier versions of SIEM (10.x and 9.x) do not use Kafka. They do not support databus connections to an 11.x based ESM, and it results in an error message when you add an older version SIEM device.
This problem occurs during the addition of a new device. Existing devices, which are on older versions, are still supported. For example, it is common to upgrade the ESM first and in doing so, the ESM can be on 11.x while the receivers and other devices are on 10.x versions. Because the other devices were present before the upgrade to ESM, the error is not encountered and it is possible to upgrade them to 11.x without issue.
It can also occur when SSH communication does not work correctly between the two devices. The ESM tries to connect and fails, which results in it being unable to determine the version.
