Addon is not working on version 0.21.1

[tankshield]

Add on is not working and showing this error

File "C:\Program Files\FreeCAD 0.21\Mod\Draft\draftutils\todo.py", line 138, in doTasks
f(arg)
File "C:\Users\USERNAME\AppData\Roaming\FreeCAD\Mod\BIM.\BimStatusBar.py", line 272, in setStatusIcons
ifc_status.set_status_widget(statuswidget)
File "C:\Users\USERNAME\AppData\Roaming\FreeCAD\Mod\FreeCAD-NativeIFC.\ifc_status.py", line 54, in set_status_widget
toggle_lock(checked)
File "C:\Users\USERNAME\AppData\Roaming\FreeCAD\Mod\FreeCAD-NativeIFC.\ifc_status.py", line 78, in toggle_lock
FreeCADGui.addWorkbenchManipulator(FreeCADGui.IFC_WBManipulator)
AttributeError: module 'FreeCADGui' has no attribute 'addWorkbenchManipulator'

21:30:30 ToDo.doTasks, Unexpected error:
<class 'AttributeError'>
in <function setStatusIcons at 0x0000027E3CA620D0>(True)