Does the Neutral light come on when the shift lever is placed in Neutral or when the operator vacates the seat?
An inoperative Neutral lamp or an open in that circuit will cause the KOPS MIL to light up.
Likewise, if there is a defect in the Mast Lock indicator lamp on the monitor panel, the KOPS MIL will light up.
The KOPS controller performs a "bulb check" when the key switch is turned on. If either of the bulbs are not working, that is a defect and the KOPS MIL will light up.
That the KOPS MIL only comes on when you select a travel position might rule out the Mast Lock circuit but I'm not sure on that.