could not run rqt_reconfigure

edit

Hi guys, i met a problem that pretty weird for me.

i can run most rqt_* except rqt_reconfigure.

Here is the Traceback from shell.

PluginManager._load_plugin() could not load plugin "rqt_reconfigure/Param":

Traceback (most recent call last):

  File "/opt/ros/melodic/lib/python2.7/dist-packages/qt_gui/plugin_handler.py", line 104, in load
    self._load()

  File "/opt/ros/melodic/lib/python2.7/dist-packages/qt_gui/plugin_handler_direct.py", line 55, in _load
    self._plugin = self._plugin_provider.load(self._instance_id.plugin_id, self._context)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_gui_py/ros_py_plugin_provider.py", line 61, in load
    return super(RosPyPluginProvider, self).load(plugin_id, plugin_context)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/qt_gui/composite_plugin_provider.py", line 72, in load
    instance = plugin_provider.load(plugin_id, plugin_context)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_gui/ros_plugin_provider.py", line 106, in load
    return class_ref(plugin_context)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_reconfigure/param_plugin.py", line 51, in __init__
    self._plugin_widget = ParamWidget(context)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_reconfigure/param_widget.py", line 105, in __init__
    self, rp, self.sig_sysmsg

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_reconfigure/node_selector_widget.py", line 102, in __init__
    self._update_nodetree_pernode()

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_reconfigure/node_selector_widget.py", line 341, in _update_nodetree_pernode
    TreenodeQstdItem.NODE_FULLPATH

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_reconfigure/treenode_qstditem.py", line 94, in __init__
    self._set_param_name(grn_current_treenode)

  File "/opt/ros/melodic/lib/python2.7/dist-packages/rqt_reconfigure/treenode_qstditem.py", line 246, in _set_param_name
    self._toplevel_treenode_name = self._list_treenode_names[0]

IndexError: list index out of range