xsmle lnincome lnrd lnarea lntech lnedu lninvest , emat(W) model(sem) re
Iteration 0:   Log-likelihood =  630.05501  (not concave)
Iteration 1:   Log-likelihood =  904.28793  (not concave)
Iteration 2:   Log-likelihood =  1396.1622  (not concave)
Iteration 3:   Log-likelihood =  1528.5458  
Iteration 4:   Log-likelihood =  1550.8881  
Iteration 5:   Log-likelihood =  1551.8784  
Iteration 6:   Log-likelihood =  1552.2775  
Iteration 7:   Log-likelihood =  1552.2997  (backed up)
Iteration 8:   Log-likelihood =  1552.3025  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 9:   Log-likelihood =  1552.3029  (backed up)
numerical derivatives are approximate
nearby values are missing
Hessian is not negative semidefinite
r(430);
点开这个430之后，出现这种错误解释
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[P]     error . . . . . . . . . . . . . . . . . . . . . . . .  Return code 430
        convergence not achieved;
        You have estimated a maximum likelihood model, and Stata's
        maximization procedure failed to converge to a solution;
        see [R] maximize.  Check if the model is identified.
Web resources from Stata and other users
想请教一下大家，这个问题怎么处理？