assert parent_field is None, parent_field
File "/home/hedayat/.local/lib/python2.7/site-packages/tryton/gui/window/view_form/view/screen_container.py", line 134, in changed
res = self.screen.search_complete(self.get_text())
File "/home/hedayat/.local/lib/python2.7/site-packages/tryton/gui/window/view_form/screen/screen.py", line 140, in search_complete
res = list(r for r in parsed_tree.complete() \
File "/home/hedayat/.local/lib/python2.7/site-packages/tryton/gui/window/view_form/screen/screen.py", line 140, in
res = list(r for r in parsed_tree.complete() \
File "/home/hedayat/.local/lib/python2.7/site-packages/tryton/common/tdp.py", line 328, in complete
right = tuple(self.right.complete(parent_field=field))
File "/home/hedayat/.local/lib/python2.7/site-packages/tryton/common/tdp.py", line 138, in complete
right = self.right and tuple(self.right.complete(parent_field)) or ('',)
File "/home/hedayat/.local/lib/python2.7/site-packages/tryton/common/tdp.py", line 138, in complete
right = self.right and tuple(self.right.complete(parent_field)) or ('',)
File "/home/hedayat/.local/lib/python2.7/site-packages/tryton/common/tdp.py", line 319, in complete
assert parent_field is None, parent_field