Cause

You tried to attach a QoS policy to a virtual interface (VIF) where you did not also attach a QoS policy to the trunk interface that the VIF belongs to.

You will trigger this error if you use a command like this:

set interfaces dataplane <interface-name> vif <vif-id> policy qos <policy-name>

without a corresponding command like this:

set interfaces dataplane <interface-name> policy qos <policy-name>