error: Unorientable shape, shape.check(True)

[brst]

Code: Select all

 p = Part.read("C:/temp/error152.brp")
p.isValid()
#False
p.check(True)
#Traceback (most recent call last):
 # File "<input>", line 1, in <module>
#ValueError: Unorientable shape
#Unorientable shape
#No error
#No error

Has anyone an idea what leads to this error?