[R] Error in matrix (unlist(value, recursive = FALSE, use.names = FALSE), nrow = nr, : attempt to set an attribute on NULL

[R. Michael Weylandt]

On Tue, Oct 9, 2012 at 10:54 PM, marsyxp <marsyxp at gmail.com> wrote:
> I am using Donlp2 package to solve a non-linear problem, but there's an error
> I always meet:
>
> Error in matrix(unlist(value, recursive = FALSE, use.names = FALSE), nrow =
> nr,  :
>   attempt to set an attribute on NULL
>
> I have been suffering from this bug for a long time. I'll be very grateful
> if somebody could help me -_-
>

This actually seems somewhat buggy: likely something internal is
giving a NULL instead of a "real" value leading to the problems you
see. You'll want to report this to the package maintainer (the only
one who can fix it): to do so, use the maintainer() function to get
contact info.

He'll probably really appreciate it if your bug report includes a
reproducible example following the advice here:
http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example

Michael