Hi all,
I am trying to impute my missing values but i i get an error message i can't figure out what is wrong. the summarize command gives me the table below

Variable | Obs Mean Std. Dev. Min Max
-------------+---------------------------------------------------------
dummyid | 500 28741.7 29538.71 919 97213
bodyfatbmi | 500 29.07252 5.741849 15.9 53.9
salivasali~w | 500 81.89784 55.9216 1.31 276.71
plasmasali~l | 478 30.8422 12.9376 3.19 72.42
glucoseact | 494 5.742591 2.098976 3.7 19.1


i can see missing values in plasmasalivaryamyalseul glucoseact variables, which i register for imputation.
then i run the code below but i get amessage saying:

glucoseact: missing imputed values produced
This may occur when imputation variables are used as independent variables or when independent variables contain
missing values. You can specify option force if you wish to proceed anyway

What I am doing wrong?


Code:
mi set wide mi register imputed plasmasalivaryamyalseul glucoseact mi describe mi impute chained (regress) plasmasalivaryamyalseul glucoseact = bodyfatbmi salivasalivaryamylaseumlnew, add (20) rseed(20) note: missing-value pattern is monotone; no iteration performed