dbus - Calibre Startup Error : Bus Name already exists

I am unable to launch calibre application. I tried re-installing it. Yet, it still gives me the following message every time.

calibre, version 2.55.0
ERROR: Startup error: There was an error during calibre startup. Parts of calibre may not function. Click Show details to learn more.

Traceback (most recent call last):
  File "/usr/lib/calibre/calibre/gui2/main.py", line 276, in initialize_db_stage2
    self.start_gui(db)
  File "/usr/lib/calibre/calibre/gui2/main.py", line 216, in start_gui
    main.initialize(self.library_path, db, self.listener, self.actions)
  File "/usr/lib/calibre/calibre/gui2/ui.py", line 261, in initialize

    self.system_tray_icon = factory(app_id='com.calibre-ebook.gui').create_system_tray_icon(parent=self, title='calibre')
  File "/usr/lib/calibre/calibre/gui2/dbus_export/widgets.py", line 232, in create_system_tray_icon
    ans = StatusNotifierItem(parent=parent, title=title, app_id=self.app_id, category=category)
  File "/usr/lib/calibre/calibre/gui2/dbus_export/tray.py", line 44, in __init__
    self.dbus_api = StatusNotifierItemAPI(self, **kw)
  File "/usr/lib/calibre/calibre/gui2/dbus_export/tray.py", line 114, in __init__
    self.dbus_name = BusName(self.name, bus=bus, do_not_queue=True)
  File "/usr/lib/calibre/calibre/utils/dbus_service.py", line 238, in __new__
    raise NameExistsException(name)
NameExistsException: Bus name already exists: org.kde.StatusNotifierItem-3230-1

Need help to fix this problem.