pspice仿真出问题，求解决？

在仿真时出现如下问题：

ERROR -- Model MUR2510 used by D_D1 is undefined
ERROR -- Model MUR2510 used by D_D2 is undefined
ERROR -- Model MUR2510 used by D_D3 is undefined
ERROR -- Model MUR2510 used by D_D4 is undefined
ERROR -- Model IRF250 used by M_M5 is undefined
ERROR -- Model IRF250 used by M_M6 is undefined
ERROR -- Model IRF250 used by M_M7 is undefined
ERROR -- Model IRF250 used by M_M8 is undefined

望高人不吝赐教，谢谢！