st: error message running xtmixed with ml

[Maureen Brinkworth <meb308@mail.harvard.edu>]

Hello,

I'm trying to run a multilevel model using xtmixed.  I've run the
model sucsessfully with the variables I need using the code below:

xtmixed s_seft neg_valence pos_valence t_posbiastsrneg t_posbiastsrpos
genmatch racematch School1 School2 School3 School4  || t_id:

However, when I add the option "mle" or "ml"  (see code below) to get
the maximum likelihood estimation I receive an unending error (also
below) that forces me to exit out of the program -- it won't even let
me stop the script.  What does this mean?  Is there any advice for how
to correct what I'm doing wrong?

Thank you in advance for your help!
Maureen


xtmixed s_seft neg_valence pos_valence t_posbiastsrneg t_posbiastsrpos
genmatch racematch School1 School2 School3 School4  || t_id:, mle


Iteration 0:   log likelihood = -464.45172
numerical derivatives are approximate
nearby values are missing
Iteration 1:   log likelihood = -462.89916
numerical derivatives are approximate
nearby values are missing
Iteration 2:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 3:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 4:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 5:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 6:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 7:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 8:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
nearby values are missing
Iteration 9:   log likelihood = -462.89916  (backed up)
numerical derivatives are approximate
flat or discontinuous region encountered
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