ID 485949 - Creating a lxifc.LogListener leaves a Modo process open when closing the main Modo application

Problem summary
Creating a lxifc.LogListener leaves a Modo process open when closing the main Modo application
Testing the below list of listeners, only LogListener seems affected:

'ActionListener', 'AnimListener', 'AppActiveListener', 'AutoSaveListener', 'CmdSysListener', 'GLShadingListener', 'ImageProcessingListener', 'ListenerPort', 'LogListener', 'MeshListener', 'NavigationListener', 'RenderCacheListener', 'RenderProgressListener', 'SceneEvalListener', 'SceneItemListener', 'SelectionListener', 'SessionListener', 'TableauListener', 'TreeListener', 'UserValueListener', 'VectorListener'

Customer reported version
modo.15.0v1

Customer reported platform
windows10

Steps to reproduce

1) Open Modo and switch to the Scripting layout

2) In the Script Editor run the following code:

import lx
import lxu
import lxifc

class LogListener(lxifc.LogListener):
    def __init__(self):
        self.listenerService = lx.service.Listener()
        self.COM_object = lx.object.Unknown(self)
        self.listenerService.AddListener(self.COM_object)

LogListener()

3) Close Modo

4) Open Task Manager/System Monitor, a Modo process will still be running
*On Windows it will have moved out of the top Appa group and into Background processes

Expected behaviour
For Modo to fully close

Actual behaviour
A Modo process is left running in the background after starting a LogListener:

​

Workaround
Kill the background process manually or add a SessionListener that removes each listener explicitly on Shutdown

Reproduced by support
This bug has been reproduced in:
Modo 15.1v1 - Windows 10, CentOS 7.5
Modo 15.0v1 - Windows 10, CentOS 7.5 - regression

Unable to reproduce bug in:
Modo 14.2v2 - Windows 10, CentOS 7.5

Earliest version tested
Modo 14.2v2 - This issue doesn't appear in this version and has regressed