Hi Subashish,
I faced the same issue some time ago.
The modeller is a java applet. Is java runtime installed on your system?
I had to reinstall mine - Java SE - Downloads | Oracle Technology Network | Oracle
Download and install JRE.
Also - make sure to activate SICF service:
jnet_handler (sap/public/bsp/sap/public/graphics/jnet_handler).
Notes to check: 717921 and 1152983.
Best regards,
Pavel