Simple network topology with DCE-Cradle PPP Protocol Problem

[HA]

Hi,

I am trying to simulate the following scenario using ns3.24 + DCE Linux 1.7 (net-next-sim-2.6.36):

Wireless Station (802.11n 5 GHz) <--> Access Point (802.11n 5 GHz) <--Point to Point Link--> Router <--Point to Point Link--> End Server.

The End Server contains OnOff/Bulk Application and the wireless station has PacketSink Application. I have attached the script file. When I run the simulation, I get the following error:

assert failed. cond="false", msg="PPP Protocol number not defined!", file=../src/point-to-point/model/point-to-point-net-device.cc, line=668

terminate called without an active exception

However, if I run the simulation again but without DCE i.e. native ns3 Stack. Things work perfectly. 

Any help regarding the error is appreciated.