If you ever come across the below exception when running WSO2 Enterprise Integrator 6.4, here is the fix. This error occurs when you have multiple IP addresses from different networks configured in your etc/hosts as below. 10.xxx.x.xxx localhost 192.xxx.x.xxx localhost So simply, removing the unnecessary one and leaving the one of the network that you are currently connected to should resolve this issue. 10.xxx.x.xxx localhost