[R-sig-ME] error in LMM fit

[Douglas Bates]

On Wed, Oct 28, 2009 at 1:11 PM, Bernet Kato <b_s_kato at yahoo.com> wrote:
> Dear Prof. Bates,
>
> I am fitting a linear mixed model using the lmer routine and I am getting
> the error message below:
>
> Error in mer_finalize(ans) : Calculated PWRSS for a LMM is negative
> In addition: Warning message:
> 1: In mer_finalize(ans) : false convergence (8)
>
>  I am not sure what is causing this error and how to deal with it. Please
> advise me.

It is best to send queries like this to the
R-SIG-Mixed-Models at R-project.org mailing list.  When doing so please
include a reproducible example and the output of

sessionInfo()

so we can tell which version of the lme4 package you are using and in
what environment.

I have taken the liberty of copying the list on this reply.