The following are possible problems that could occur together with solutions to overcome them:
Stratos2 Core services are not started
If your Stratos2 setup is running properly there should be a minimum five Java processes running when the script ends. These are ELB, S2 Agent, SC, CC and BAM.
Started Carbon Cartridge instance has not joined ELB
The reason that the Carbon Cartridge instance has not joined the ELB, could be due to the ports of the IaaS security group not being opened. Please see the Common IaaS Configurations section to find the ports that should be opened and open the respective ports.