Hello

At the moment I'm trying to do regressions with panel data.
If I make a OLS regression with the panel data it works without any problem. My used codes are as follows:
Code:
regress D.(viol_crime_rate asylum_pop a8_pop) i.Year [aw=adult_pop], vce(cluster panel_id)



However, if I try to make a fixed-effect panel regression, I get as a result "negative weights encountered". My used codes are as follows:
Code:
xtreg viol_crime_rate asylum_pop a8_pop i.Year [aw=avg_adult_pop], fe vce(cluster panel_id)
Does anybody know, how to solve this problem?

Thank you very much for your help.

Best
LM