abaqus梁单元弹簧杆系模型模态分析错误？

采用abaqus建立了结构的梁单元弹簧杆系模型，采用连接器施加拉压弹簧和转动弹簧，模态分析报错Three factorizations in a row failed. Check the model. It is possible that the model contains the kinematic coupling definition set up in a way that a degree of freedom has neither mass nor stiffness.