I'm a new of STATA , I have some data for analysis Multiple logistic regression and I got error r(2000).


sw logit druguse q1 q2 q3 q4 q5 q6 q7 q8 q9 q10 q11 q12 q13 q14 q15, pr (0.05)
could not estimate full model
no observations
r(2000);


I'm trying to understand what the problem is here and how to overcome it. then I saw your answer on STATA forum
Can you help me for resolved this ?. Thank you so much and sorry for my poor English.