Problem with nDMaterial('PressureIndependMultiYield')

[ma-simple]

Hello Dr. Zhu:

First of all, I’m very glad to use OpenSeesPy — it's an excellent platform, and I truly appreciate the efforts of the development team and contributors!

However, I’m encountering the following warning and error when using the PressureIndependMultiYield material:

WARNING invalid PressureIndependMultiYield numberOfYieldSurf
opensees.OpenSeesError: See stderr output

my test code

import openseespy.opensees as ops
ops.wipe()
ops.model('basic', '-ndm', 2, '-ndf', 2)

ops.nDMaterial("PressureIndependMultiYield",
               1,          # matTag
               2,          # nd
               1800.0,     # rho
               6.0e4,      # G
               3.0e5,      # B
               37.0,       # frictionAng
               0.1,        # peakShearStrain
               100.0,      # refPress
               0.0)        # pressDependCoeff

I also tried specifying numberOfYieldSurf = 16 with 16 (or 20) pairs of (strainRatio, stressRatio), but the warning and crash persist.
What I would like to know:
What exactly causes the invalid numberOfYieldSurf warning?
Is defining yield surfaces manually mandatory, even when not specifying -numberOfYieldSurf?

Thank you very much~

[zhuminjie]

numberOfYieldSurf is required. Adding it after your last parameter. There is no '-numberOfYieldSurf' option just give the number.

[ma-simple]

Sincere thanks for your response, Dr. Zhu. I have tried once again to add the numberOfYieldSurf parameter at the end, both with and without the dash (-), but it still doesn't work. Could you please advise where the issue might be?
I'll post my code