Exception occurred in traits notification handler. When run command mayavi2

**PLEASE help me What/ Where to check to fix this error.**
I am running is on CentOS 7 -1810.

```
usr/local/lib64/python3.6/site-packages/traits/etsconfig/etsconfig.py:420: UserWarning: Environment variable "HOME" not set, setting home directory to /tmp
% (environment_variable, parent_directory)
Exception occurred in traits notification handler.
Please check the log file for details.
Exception occurred in traits notification handler for object: , trait: application, old value: None, new value:
Traceback (most recent call last):
File "/usr/local/lib64/python3.6/site-packages/traits/trait_notifiers.py", line 654, in _dispatch_change_event
self.dispatch(handler, *args)
File "/usr/local/lib64/python3.6/site-packages/traits/trait_notifiers.py", line 553, in dispatch
handler(*args)
File "/usr/local/lib64/python3.6/site-packages/traits/traits_listener.py", line 498, in handle_simple
self.next.register(new)
File "/usr/local/lib64/python3.6/site-packages/traits/traits_listener.py", line 464, in register
value = getattr(self, type)(new, name, False)
File "/usr/local/lib64/python3.6/site-packages/traits/traits_listener.py", line 738, in _register_simple
return next.register(getattr(object, name))
File "/usr/local/lib/python3.6/site-packages/envisage/ui/workbench/workbench_application.py", line 140, in _gui_default
return GUI(splash_screen=self.splash_screen)
File "/usr/local/lib64/python3.6/site-packages/mayavi/plugins/mayavi_workbench_application.py", line 121, in _splash_screen_default
show_log_messages = True,
File "/usr/local/lib/python3.6/site-packages/pyface/base_toolkit.py", line 178, in __init__
raise NotImplementedError(msg % (toolkit, package, name))
NotImplementedError: the null pyface.ui.null backend doesn't implement splash_screen:SplashScreen
Exception occurred in traits notification handler for object: , trait: application, old value: None, new value:
Traceback (most recent call last):
File "/usr/local/lib64/python3.6/site-packages/traits/trait_notifiers.py", line 654, in _dispatch_change_event
self.dispatch(handler, *args)
File "/usr/local/lib64/python3.6/site-packages/traits/trait_notifiers.py", line 553, in dispatch
handler(*args)
File "/usr/local/lib64/python3.6/site-packages/traits/traits_listener.py", line 498, in handle_simple
self.next.register(new)
File "/usr/local/lib64/python3.6/site-packages/traits/traits_listener.py", line 464, in register
value = getattr(self, type)(new, name, False)
File "/usr/local/lib64/python3.6/site-packages/traits/traits_listener.py", line 738, in _register_simple
return next.register(getattr(object, name))
File "/usr/local/lib/python3.6/site-packages/envisage/ui/workbench/workbench_application.py", line 140, in _gui_default
return GUI(splash_screen=self.splash_screen)
File "/usr/local/lib64/python3.6/site-packages/mayavi/plugins/mayavi_workbench_application.py", line 121, in _splash_screen_default
show_log_messages = True,
File "/usr/local/lib/python3.6/site-packages/pyface/base_toolkit.py", line 178, in __init__
raise NotImplementedError(msg % (toolkit, package, name))
NotImplementedError: the null pyface.ui.null backend doesn't implement splash_screen:SplashScreen
Traceback (most recent call last):
File "/usr/local/bin/mayavi2", line 11, in
load_entry_point('mayavi==4.7.1', 'gui_scripts', 'mayavi2')()
File "/usr/local/lib64/python3.6/site-packages/mayavi/scripts/mayavi2.py", line 602, in main
mayavi.main(sys.argv[1:])
File "/usr/local/lib64/python3.6/site-packages/mayavi/plugins/app.py", line 195, in main
app.run()
File "/usr/local/lib64/python3.6/site-packages/mayavi/plugins/mayavi_workbench_application.py", line 73, in run
gui = self.gui
File "/usr/local/lib/python3.6/site-packages/envisage/ui/workbench/workbench_application.py", line 140, in _gui_default
return GUI(splash_screen=self.splash_screen)
File "/usr/local/lib64/python3.6/site-packages/mayavi/plugins/mayavi_workbench_application.py", line 121, in _splash_screen_default
show_log_messages = True,
File "/usr/local/lib/python3.6/site-packages/pyface/base_toolkit.py", line 178, in __init__
raise NotImplementedError(msg % (toolkit, package, name))
NotImplementedError: the null pyface.ui.null backend doesn't implement splash_screen:SplashScreen
```