hi amrita,
i helped my colleague to solve the same issue as you met
here is what we did
configure the smp profile in appbuilder as followed
profile name:smp
server url:http://<host>:8080
application id: com.lawrence.flight (the application id you created)
security config: flight (the security setting which you created in smp which used the http authorization)
Uncheck allow anonymous login
Username: p160381
password: *******
hope it could fix your issue
enjoy smp 3.0
best regards
lawrence