Hi all,

I'm doing a multilevel negative binomial regression analysis, using the LME4 package.

I created the following script:

R< nb <- glmer.nb(MOP ~ age+experience+(1|SubjectID), data = Data, interval = log(th) + c(-3, 3), tol = 5e-5, verbose = FALSE, nb.control = NULL, initCtrl = list(limit = 20, eps = 2*tol, trace = verbose, theta = NULL))

When I run this code, it gives me the following outcome:

**object 'tol' not found**

I tried to install packages MASS and Optimize, however R says these packages aren't available for R version 3.4.3.

Is there anyone who worked with this analysis and can help me with this?

Thank you in advance!