st: tsset - repeated time values within panel

[emanuele mazzini <madsoenistata@gmail.com>]

Dear Stata users,
I have a panel bilateral dataset with country pairs from year 1950 to
2006 and experiencing the error message repeated time values within
panel when typing tsset. I have already read some messages sen by
other people experiencing the same issue, and also I tried to follow
the suggestion of the guide, but still cannot understand why i got
that.
To be more precise, as mine is a bilateral dataset, I have to say that
every observation is identified by three variables (cty1, cty2 and
year) so may be the problem relates to this, but obviously I am not
sure.
Finally, I am not really interested in the command per se, but the
point is to replace some missing values which are time-constant and
for which I do have data for the previous/following years.
Can anybody help me to deal with this?

Thank you very much in advance,
Regards,
Emanuele.
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