st: mi error r(119) appears in a not mi set database

[Lucas Andrés Salas D <lucassalas@gmail.com>]

Dear statalisters,

We have found a recurrent error message with some databases when
working with Stata/SE 12.1. We work with several collapsed long and
complete long panel databases which are not mi set.

This time I was working with an unbalanced long panel database (n=120
subjects with a  yearly follow up from 1945 to 2011).

As I tried to xtset my database to obtain some descriptive summary
before collapsing I got the following error:

xtset id2 year, yearly
no; data are mi set
    Use mi xtset to set or query these data; mi xtset has the same
syntax as xtset.

    Perhaps you did not type xtset.  Some commands call xtset to
obtain information about the settings.  In that case, that command is
not appropriate
    for running directly on mi data.  Use mi extract to select the
data on which you want to run the command, which is probably m=0.
r(119);

My database is not imputed neither any of the original ones (I tried
with the mother databases and they worked just fine when xtset).

I tried mi unset  unsuccessfully:

mi unset
_mi_m not found

mi xtset id2 year, yearly
_mi_m not found


I tried to save as old Stata 9/10 and reopen, but the error persist.

Finally I decided to outsheet/insheet the database and then xtset worked:

xtset id2 year, yearly
       panel variable:  id2 (unbalanced)
        time variable:  year, 1945 to 2011
                delta:  1 year


Any ideas of what is happening and how to solve it?

Best,

Lucas
-- 
Lucas A Salas, MD MSc MPH
PhD researcher
CREAL - Centre for Research in Environmental Epidemiology
ISGlobal alliance
Barcelona Biomedical Research Park - PRBB
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