Following errors appear in console when I'm trying to use tools in Draft
workbench (tools are not working).

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Running the Python command 'Draft_ShapeString' failed:
Traceback (most recent call last):
  File "/usr/lib64/FreeCAD/Mod/Draft/draftguitools/gui_shapestrings.py", line
72, in Activated
    super(ShapeString, self).Activated(name="ShapeString")
  File "/usr/lib64/FreeCAD/Mod/Draft/draftguitools/gui_base_original.py", line
287, in Activated
    super(Creator, self).Activated(name, noplanesetup)
  File "/usr/lib64/FreeCAD/Mod/Draft/draftguitools/gui_base_original.py", line
152, in Activated
    Gui.Snapper.setTrackers()
  File "/usr/lib64/FreeCAD/Mod/Draft/draftguitools/gui_snapper.py", line 1672,
in setTrackers
    self.grid = trackers.gridTracker()
  File "/usr/lib64/FreeCAD/Mod/Draft/draftguitools/gui_trackers.py", line 989,
in __init__
    self.text1.string = " "
  File "/usr/lib64/python3.6/site-packages/pivy/coin.py", line 51919, in
<lambda>
    __setattr__ = lambda self, name, value: _swig_setattr(self, SoAsciiText,
name, value)
  File "/usr/lib64/python3.6/site-packages/pivy/coin.py", line 80, in
_swig_setattr
    return _swig_setattr_nondynamic(self, class_type, name, value, 0)
  File "/usr/lib64/python3.6/site-packages/pivy/coin.py", line 69, in
_swig_setattr_nondynamic
    return method(self, value)

in method 'SoAsciiText_string_set', argument 2 of type 'SoMFString *'
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