This is more a patsy error which generates the design matrix. I agree with @falk it is something to do with your input - try entering the predictors one by one in your linear model and check which one is causing the error.
This is more a patsy error which generates the design matrix. I agree with @falk it is something to do with your input - try entering the predictors one by one in your linear model and check which one is causing the error.