RuntimeError when pressing TAB

[anitagraser]

To reproduce, run l = iface.activeLayer() followed by typing l. and pressing TAB. This results in:

2018-11-18T11:24:28     WARNING    Traceback (most recent call last):
              File "C:\OSGEO4~1\apps\Python37\lib\site-packages\qtconsole\base_frontend_mixin.py", line 138, in _dispatch
              handler(msg)
              File "C:\OSGEO4~1\apps\Python37\lib\site-packages\qtconsole\jupyter_widget.py", line 174, in _handle_complete_reply
              self._complete_with_items(cursor, matches)
              File "C:\OSGEO4~1\apps\Python37\lib\site-packages\qtconsole\console_widget.py", line 1026, in _complete_with_items
              self._completion_widget.show_items(cursor, items)
              File "C:\OSGEO4~1\apps\Python37\lib\site-packages\qtconsole\completion_plain.py", line 56, in show_items
              strng = text.columnize(items)
              File "C:/Users/anita/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\IPyConsole\IPyConsole.py", line 375, in new_columnize
              return old_columnize(items, separator, displaywidth)
              File "C:/Users/anita/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\IPyConsole\IPyConsole.py", line 375, in new_columnize
              return old_columnize(items, separator, displaywidth)
              File "C:/Users/anita/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\IPyConsole\IPyConsole.py", line 375, in new_columnize
              return old_columnize(items, separator, displaywidth)
              File "C:/Users/anita/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\IPyConsole\IPyConsole.py", line 374, in new_columnize
              displaywidth = control.get_columns()
              File "C:/Users/anita/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\IPyConsole\IPyConsole.py", line 305, in get_columns
              font_width = QFontMetrics(self.font).width(' ')
              File "C:\OSGEO4~1\apps\Python37\lib\site-packages\qtconsole\console_widget.py", line 726, in _get_font
              return self._control.document().defaultFont()
             RuntimeError: wrapped C/C++ object of type QTextEdit has been deleted