Modeling issues of PML elements in OpenSeesPy

[HUxuwen]

Dear STKO team:
I am currently modeling the PML2D element. After declaring in Python as ops.model('basic', '-ndm', 2, '-ndf', 5), I still encounter an error when modeling according to the PML2D element instructions in the OpenSees manual: ops.element('PML', eleTag, node1, node2, node3, node4, E, nu, rho, 1, 1.0, 2, 1e-8, 50, 1, 0.0, 0.0,).
The error message is: Error in abaqus PML2D. Variable NDOFEL must exceed 2*NNODE Perfectly Matched Layer 2D (PML) element - Written by W. Zhang, E. Taciroglu, L. Chen, and P. Arduino, from UCLA, UCLA, University of Washington, and University of Washington, respectively. Why is this so?
I am looking forward to your reply with great eagerness.

[STKO Team]

Does the error appears soon after you create the element?