Help fitting a poisson glmer (getting an error message)

Question

I am trying to fit a Poisson glmer model in R, to determine if 4 experimental treatments affected the rate at which plants developed new branches over time. New branches were counted after 35, 70 and 83 days and data were organised as follows:

treatment  replicate.plant  time      branches 
   a         ID4             35          0           
   a         ID4             70          1        
   a         ID4             83          1
   a         ID12            35          1
   a         ID12            70          3
   a         ID12            83          8

Loading the package lme4 , I ran the following model:

mod<-glmer(branches ~ treatment + (1|time),
             family=poisson, 
             data=dataset)

but I obtain the following error message:

Error in get(name, envir = asNamespace(pkg), inherits = FALSE) :
object '.setDummyField' not found

Can anyone please give me an indication of why I am getting this error and what does it mean? Any advicse on how to make this model run will be greatly appreciated.

Answer 1

This is a known issue, see here: https://github.com/lme4/lme4/issues/54

The problem seems to be limited to R version 3.0.0 . You should update to a more recent version.