请问stata跑多项probit的时候停不下来是什么情况？

Iteration 4545: log likelihood = -135.48589  (not concave)
Iteration 4546: log likelihood = -135.48589  (not concave)
Iteration 4547: log likelihood = -135.48589  (not concave)
Iteration 4548: log likelihood = -135.48589  (not concave)
Iteration 4549: log likelihood = -135.48589  (not concave)
Iteration 4550: log likelihood = -135.48589  (not concave)
Iteration 4551: log likelihood = -135.48589  (not concave)
Iteration 4552: log likelihood = -135.48589  (not concave)

……就这么跑了下去，

我的原指令是mprobit  y1 gender age education job ……,nolog, base(politics)