Loading third party modules in JBOSS_HOME/modules/system

Issue

Trying to include third-party modules. When it's put in the com/module under JBOSS_HOME/modules/system/custom directory, The error is thrown:

 ERROR [org.jboss.as.controller.management-operation] (ServerService Thread Pool -- 38) WFLYCTL0013: Operation ("add") failed - address: ([
    ("subsystem" => "subsystem"),
    ("jdbc-driver" => "name")
]) - failure description: "WFLYJCA0041: Failed to load module for driver [com.module]"

However, when it's placed under JBOSS_HOME/modules directory and restart the server, it starts without errors. And loads libraries properly.