Cannot compute outward normal for vertices surface

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Hello When defining the ceiling in C#, the following error is displayed, I do not understand the source of the error, thank you for your guidance.

Cannot compute outward normal for vertices [[7.49582, 4.56265, 3.2004], [1.49582, 4.56265, 3.2004], [7.49582, 1.56265, 3.2004], [1.49582, 1.56265, 3.2004]], surface name = 'Surface 1'