why occured this error?

[cucuro11]

I cannot access my manage dashboard.
In Splunk Enterprise 8.0.2.1 And Search Header Cluster.
If you have seen 500 Internal Server Error like below, help me please.

==============error log=============
2020-03-27 18:49:54,279 ERROR   [5e7dcc420a7fb6f4323890] error:335 - Traceback (most recent call last):
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/cherrypy/_cprequest.py", line 628, in respond
    self._do_respond(path_info)
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/cherrypy/_cprequest.py", line 687, in _do_respond
    response.body = self.handler()
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/cherrypy/lib/encoding.py", line 219, in __call__
    self.body = self.oldhandler(*args, **kwargs)
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/htmlinjectiontoolfactory.py", line 75, in wrapper
    resp = handler(*args, **kwargs)
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/cherrypy/_cpdispatch.py", line 54, in __call__
    return self.callable(*self.args, **self.kwargs)
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/routes.py", line 383, in default
    return route.target(self, **kw)
  File "</SPLUNK/splunk_sh01/lib/python3.7/site-packages/decorator.py:decorator-gen-632>", line 2, in advancedsearch
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/decorators.py", line 40, in rundecs
    return fn(*a, **kw)
  File "</SPLUNK/splunk_sh01/lib/python3.7/site-packages/decorator.py:decorator-gen-630>", line 2, in advancedsearch
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/decorators.py", line 118, in check
    return fn(self, *a, **kw)
  File "</SPLUNK/splunk_sh01/lib/python3.7/site-packages/decorator.py:decorator-gen-629>", line 2, in advancedsearch
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/decorators.py", line 166, in validate_ip
    return fn(self, *a, **kw)
  File "</SPLUNK/splunk_sh01/lib/python3.7/site-packages/decorator.py:decorator-gen-628>", line 2, in advancedsearch
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/decorators.py", line 245, in preform_sso_check
    return fn(self, *a, **kw)
  File "</SPLUNK/splunk_sh01/lib/python3.7/site-packages/decorator.py:decorator-gen-627>", line 2, in advancedsearch
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/decorators.py", line 284, in check_login
    return fn(self, *a, **kw)
  File "</SPLUNK/splunk_sh01/lib/python3.7/site-packages/decorator.py:decorator-gen-626>", line 2, in advancedsearch
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/lib/decorators.py", line 304, in handle_exceptions
    return fn(self, *a, **kw)
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/controllers/admin.py", line 2995, in advancedsearch
    'breadcrumbs': self.generateBreadcrumbs(namespace, 'advancedsearch'),
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/controllers/admin.py", line 1381, in render_admin_template
    args =  root.app.buildViewTemplate(namespace, ADMIN_VIEW_NAME, render_invisible=True, build_nav=False, include_app_css_assets=False)
  File "/SPLUNK/splunk_sh01/lib/python3.7/site-packages/splunk/appserver/mrsparkle/controllers/view.py", line 806, in buildViewTemplate
    viewList.sort(key=lambda x: x['label'])
TypeError: '<' not supported between instances of 'NoneType' and 'str'

[manjunathmeti]

There is some issue with your dashboard xml code. Check if dashboard label is there or not. If not add label to dashboard and check. Also check labels for all other dashboards exist in the app.

 <dashboard>
   <label>label</label>
 <dashboard>

[cucuro11]

Thank you for your help.