Natbib Newblock Undefined Error with Informs3 Document Class

I am trying to submit an article to a Journal that uses the INFORMS3 document class. I used BibDesk to generate the BIB file and TexShop to compile the source file. Here is the TEX file, a minimum (non)-working example:

% LaTeX Article Template
documentclass[moor]{informs3}
usepackage{latexsym,amscd}
usepackage[mathscr]{euscript}
usepackage{tabstackengine}
usepackage{mathtools}
usepackage[round]{natbib}

stackMath

newcolumntype{C}[1]{>{centeringarraybackslash$}m{#1}<{$}}
newlength{mycolwd}                                         % array column width
settowidth{mycolwd}{$-frac{3}{4}$}% "width" of $e^{-frac{i}{hbar}|A|t$; largest element in array

%smartqed
%newcommand{argmax}{operatornamewithlimits{argmax}}

setlength{jot}{.2in}
% Set the beginning of a LaTeX document
newtheorem{proposition}{Proposition}
newtheorem{lemma}{Lemma}
newtheorem{theorem}{Theorem}
newtheorem{corollary}{Corollary}
newtheorem{definition}{Definition}
%newtheorem{proof}{Proof}

begin{document}

RUNAUTHOR{X}
RUNTITLE{X}
TITLE{X}
AUTHOR{X}
ABSTRACT{
Sample
}
KEYWORDS{
Sample
}
maketitle

section{Introduction}

There have been a number of alternative proofs of this result offered over the years; e.g. cite{Spinetto:1974aa}, cite{Charnes:1967aa}, and the methods employed have turned out to be of almost as much interest as the result itself. For example,  

bibliographystyle{informs2014}
bibliography{BalancedSetsELSArticleBibTex}{}

end{document}

From within TexShop I can compile once with Latex and then twice with BibTex, no errors. However, when I then go to compile with Latex again, I get the following error:

Package natbib Warning: Citation 'Spinetto:1974aa' on page 2 undefined on input line 43

Package natbib Warning: Citation 'Charnes:1967aa' on page 2 undefined on input line 43.

(./BibTexTest.bbl

./BibTexTest.bbl:1: LaTeX Error: newblock undefined.

...

l.1 begin{the bibliography}{2}

Here is the bbl file

begin{thebibliography}{2}
providecommand{natexlab}[1]{#1}
providecommand{url}[1]{texttt{#1}}
providecommand{urlprefix}{URL }

bibitem[{Charnes protectBIBand{} Kortanek(1967)}]{Charnes:1967aa}
Charnes A, Kortanek K (1967) On balanced sets, cores and linear programming.
  emph{Cahiers du Centre d'Etudes de Recherche Operationelle} 9:32--43.

bibitem[{Spinetto(1974)}]{Spinetto:1974aa}
Spinetto R (1974) The geometry of solution concepts for {it n}-person
  cooperative games. emph{Manage Sci} 20:1292--1299.

end{thebibliography}

I am at my wit’s end. I had no problem formatting the paper and bibliography with the ectaart or svjour3 or elsarticle classes, but I need it (of course) for INFORMS3 and I can’t submit until I get this last piece done.

Any thoughts or pointers would be appreciated.

EDIT: I just came across a suggestion on a Google groups that magically fixed the issue (or at least allowed the generation of the References which is what I need to be able to submit): At the bottom of the TEX file, just before the bibliographystyle, I added the line:

newcommand{newblock}{}

usepackage{natbib}
bibpunct[, ]{(}{)}{,}{a}{}{,}%
defbibfont{small}%
defbibsep{smallskipamount}%
defbibhang{24pt}%
defnewblock{ }%
defBIBand{and}%