VAR Model Error: Repeated Time Values in Sample

[Julia Sophie]

hello all,
I would like to use the code Var to determine the lags between the following variables:


Unfortunately, I always get the following error message: repeated time values in sample.

However, I do not understand why this is problematic. The Var targets panel data, where it is logical that repeated time values appear.

Thanks in advance for the help

*Declare data set as time series
xtset ID year, yearly


*Determination of the Lags between Conflict Intensity and Opportunity Recognition
var confli_intensity_zero opport_recog_zero, lags(1/6)