I try to do a Monte Carlo simulation with a very simple SEM. I've got 2 latent variables and 3 categorical indicators with 3 categories per latent variable (see the attachment).
If I run my model (code is also in the attachment) I receive different error messages:
-"In model 'Title' NPSOL returned a non-zero status code 1. The final iterate satisfies the optimality conditions to the accuracy requested..."
-"In model 'Title' NPSOL returned a non-zero status code 6. The model does not satisfy the first-order optimality conditions..."
And in a very few case I don't receive an error message.
I read that the choice of the starting values can solve the problem, so I choose them near the "true" values but the problem still remains.
I also read that underidentification of the model could be the problem, but I fixed the variances of the error terms of the observed variables to 1 ,the means to 0 and one loading of each block to 1, so I think the model should be identified.
I would appreciate any suggestion and/or possible solutions.