If you are seeing the following error while starting the Gateway engine, the steps mentioned in the resolution may help to overcome this error
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GatewayServer com.tibco.ax.gs.runtime.GatewayRuntimeException: Initializing JMX service failed.
        at com.tibco.ax.gs.runtime.JmxServiceManager.Startup(JmxServiceManager.java:97)
        at com.tibco.ax.gs.runtime.GatewayServer.initJMXService(GatewayServer.java:507)
        at com.tibco.ax.gs.runtime.GatewayServer.init(GatewayServer.java:118)
        at com.tibco.ax.gs.runtime.GatewayServer.<init>(GatewayServer.java:81)
        at com.tibco.ax.gs.runtime.GatewayServer.Startup(GatewayServer.java:618)
Caused by: Address already in use: Address already in use: Address already in use: Address already in use
        at com.tibco.ax.fw.jmx.model.MgmtServer.init(MgmtServer.java:108)
        at com.tibco.ax.fw.jmx.model.MgmtServer.<init>(MgmtServer.java:67)
        at com.tibco.ax.fw.jmx.model.MgmtServer.getInstance(MgmtServer.java:54)
        at com.tibco.ax.fw.jmx.model.ModelBuilder.registerControlModels(ModelBuilder.java:191)
        at com.tibco.ax.fw.jmx.model.ModelBuilder.register(ModelBuilder.java:177)
        at com.tibco.ax.gs.runtime.JmxServiceManager.Startup(JmxServiceManager.java:93)
        ... 4 more
>>>
One of the possible causes for this error is that you have probably used same port number for both management as well as data port settings while creating the Gateway token.

All Environment

While creating Gateway token, if both the Management port and Data port use the same port number, then the Gateway server will give the above error while starting.

To resolve the issue, use a different port value for both the management port and data port.

To do this, create a new token and use a unique Management port and the Data port (default port numbers are: Management port=11000 and Data port=12000), and make sure that the assigned port should not be used by any other application.

For more information, please refer the Chapter 5 - "Gateway Tokens" under the "TIBCO BusinessConnect Gateway Server" and the link for the same is given below:-

<<<<<<<
https://docs.tibco.com/pub/bc/7.0.0/doc/bcgs/pdf/TIB_bc_7.0_gatewayserver%20admin%20guide.pdf?id=2
>>>>>>>
Also for reference please see the attached screenshot : Token_Settings.PNG

How to resolve "Address already in use" error while starting BusinessConnect Gateway Server?