Now I have made some changes to simplify the circuit for troubleshooting.
1. I reduce the no of ONU’s to 4 and now the “Simulation Stop” error has not appeared. But the simulation goes on indefinitely at the Buffer Selectors of OLT1-OLT4.
2. I also change Bi-directional AWG Mux/DeMux to Uni-directional Mux and DeMux so that I set the frequency for DS and US separately in Mux and DeMux. (But still same problem i.e:simulation goes on indefinitely at the Buffer Selectors of OLT1-OLT4).
3.Now I remove the Rxr Section of OLT-2,3 and 4. Only OLT1 Receive section is present. But Still same problem i.e:simulation goes on indefinitely at the Buffer Selectors of OLT1(Buffer Sel 3).
I have attached the latest Project File. I cant understand whats wrong with circuit.