The remoting subsystem creates a requirement for the org.wildfly.io.worker.default capability if no specific worker capability is configured. The problem with this is in a domain profile meant for legacy slaves, there will be no io subsystem configured, so the capability will not be present. This is leading to failures in the mixed domain tests.

A not great solution is to not record the requirement on an HC if no specific worker capability is configured. The downside is if the io subsystem isn't configured and that profile is used on a current version server, the server configuration will be inconsistent and failures will occur at boot.