Use of @xfootnotenext doesn't match its definition

I am using Elsevier LaTeX template to publish an article on an Elsevier journal and I got the following error:

165  Use of @xfootnotenext doesn't match its definition.
@ifnextchar ... reserved@d =#1def reserved@a {
                                                  #2}def reserved@b {#3}f...
l.165 maketitle

The latex code is:

%% 
%% Copyright 2019-2020 Elsevier Ltd
%% 
%% This file is part of the 'CAS Bundle'.
%% --------------------------------------
%% 
%% It may be distributed under the conditions of the LaTeX Project Public
%% License, either version 1.2 of this license or (at your option) any
%% later version. The latest version of this license is in
%%    http://www.latex-project.org/lppl.txt
%% and version 1.2 or later is part of all distributions of LaTeX
%% version 1999/12/01 or later.
%% 
%% The list of all files belonging to the 'CAS Bundle' is
%% given in the file `manifest.txt'.
%% 
%% Template article for cas-dc documentclass for 
%% double column output.

%documentclass[a4paper,fleqn,longmktitle]{cas-dc}
documentclass[a4paper,fleqn]{cas-dc}

%usepackage[authoryear,longnamesfirst]{natbib}
%usepackage[authoryear]{natbib}
usepackage[numbers,sort&compress]{natbib}

%%%Author definitions
deftsc#1{csdef{#1}{textsc{lowercase{#1}}xspace}}
tsc{WGM}
tsc{QE}
tsc{EP}
tsc{PMS}
tsc{BEC}
tsc{DE}
%%% 

begin{document}
letrefCref       
leteqrefCref     
letautorefCref   
letWriteBookmarksrelax
deffloatpagepagefraction{1}
deftextpagefraction{.001}
shorttitle{CV Radhakrishnan et~al. / Engineering Science and Technology, an International Journal}
%shortauthors{CV Radhakrishnan et~al.}
footmarks{url{https://doi.org/xx.xxxx/j.jestch.20xx.xx.xxx}
    2215-0986/begingrouptiny{©}endgroup~20xx Karabuk University. Publishing services by Elsevier B.V.
    This is an open access article under the CC BY-NC-ND license (url{http://creativecommons.org/licenses/by-nc-nd/4.0/}).
}

bookmark[named = FirstPage]{Title} % Title bookmark used in the pdf
%**************** If the title is short, stay on the first line use [mode = short_title] otherwise ******************
%***************************************** use [mode = title] below ***************************************
title [mode = title]{Title}    

% Title mark notes if desired
%tnotemark[1,2]

%tnotetext[1]{This document is the results of the research
%   project funded by the National Science Foundation.}

%tnotetext[2]{The second title footnote which is a longer text matter
%   to fill through the whole text width and overflow into
%   another line in the footnotes area of the first page.}

author[1,3]{CV Radhakrishnan}[type=editor, 
                        auid=000,bioid=1,
                        prefix=Sir,
                        %role=Researcher,
                        %orcid=0000-0001-7511-2910
                        ]
cormark[1]
%fnmark[1]                             % URL related footnote marking
ead{[email protected]}
%ead[url]{www.cvr.cc, [email protected]} % Author URL 

credit{Conceptualization of this study, Methodology, Software}

address[1]{Elsevier B.V., Radarweg 29, 1043 NX Amsterdam, The Netherlands}

author[2,3]{Han Theh Thanh}[style=chinese]

author[2,3]{CV Rajagopal}[
   %role=Co-ordinator,
   suffix=Jr,
   ]
%fnmark[2]                             % URL related footnote marking
ead{[email protected]}
%ead[URL]{www.sayahna.org}             % Author URL

credit{Data curation, Writing - Original draft preparation}

address[2]{Sayahna Foundation, Jagathy, Trivandrum 695014, India}

author
[1,3]
{Rishi T.} % If the author's name hits "Check for updates" button, use  at the break point of his/her name like {Rishi T.} or {First Middle Lastname}
% NOTE: Compile first without  then the proper separation again afterwards !!! (Not doing so, results unwanted footnote and Credit authorship contribution at the very end with credit command if used.)
cormark[2]
%fnmark[1,3]                           % URL related footnote marking
ead{[email protected]}
%ead[URL]{www.stmdocs.in}              % Author URL

address[3]{STM Document Engineering Pvt Ltd., Mepukada,
    Malayinkil, Trivandrum 695571, India}

author[4]{ Salih Baris Ozturk} % Author's name hits "Check for updates" button,  is used at the break point of his name. If  is desired at the beginning of the name, place a space just before the  as in the above example.
% NOTE: Compile first without  and the space, then the proper separation again afterwards !!! (Not doing so, results unwanted footnote and Credit authorship contribution at the very end with credit command if used.)
%cormark[1]
ead{[email protected]}

address[4]{Istanbul Technical University, Department of Electrical Engineering,
    Maslak, Istanbul 34469, Turkey}

credit{Modification for the final layout}

cortext[cor1]{Corresponding author.}
cortext[cor2]{Principal corresponding author.}
%fntext[fn1]{This is the first author footnote. but is common to third
%  author as well.}
%fntext[fn2]{Another author footnote, this is a very long footnote and
%  it should be a really long footnote. But this footnote is not yet
%  sufficiently long enough to make two lines of footnote text.}

%nonumnote{This note has no numbers. In this work we demonstrate $a_b$
%  the formation Y_1 of a new type of polariton on the interface
%  between a cuprous oxide slab and a polystyrene micro-sphere placed
%  on the slab. The evanescent field of the resonant whispering 
%  gallery mode (WGM) of the micro sphere has a substantial 
%  gradient, and therefore effectively couples with the
%  quadrupole $1S$ excitons in cuprous oxide.}

nonumnote{Peer review under responsibility of Karabuk University.}

begin{abstract} 
my abstract
end{abstract}

% If any graphical abstract is needed
%begin{graphicalabstract}
%includegraphics{figs/grabs.pdf}
%end{graphicalabstract}

% If any highlights is needed above the cover page
%begin{highlights}
%item Research highlights item 1
%item Research highlights item 2
%item Research highlights item 3
%end{highlights}

% Article history - Should only be set by an editor
received {xx Month 20xx}
revised {xx Month 20xx}
accepted {xx Month 20xx}
online {xx Month 20xx}

begin{keywords}
keyword 1 sep 
keyword 2 sep 
keyword 3 sep 
keyword 4   
end{keywords}

maketitle
section{Introduction}
The Elsevier cas-dc class is based on the
standard article class and supports almost all of the functionality of
that class.