Background

I am currently working on submitting a journal manuscript and am trying to convert my original manuscript from elsarticle class to cas-dc based on feedback and recommendations from Elsevier. My code will successfully typeset my document every other time. It runs through, creates the following error message, I re-run and then it deletes the .aux file and successfully compiles.

Error message:! Missing = inserted for ifnum.

Normally this would not be an issue but as @PhelypeOleinik pointed out in his answer to my original question, I need to successfully compile the document twice in order to get things like author and title notes to work.

Similar questions

I have looked at the following answer/questions without much success:

• Compilation problem with siunitx (returning error regarding ifnum): claims that it’s an issue with how versions are maintained and dated, suggests that user update Tex distribution. I have updated everything in MikTex and repeatedly checked for updates until no more updates were available. Issue persists.

• Missing=inserted for ifnum: no answer suggests a potential issue with beamer. I am not using beamer, do not think that it is an issue.

• Missing = inserted for ifnum error when generating bibliography using natbib : suggests deleting the bib aux file and rerunning. This wont work because I need to re-run without deleting the aux file in order to get all the notes to show up.

• Missing = inserted for ifnum. usepackage: alternately suggest look at the first answer in this list and updating packages/MikTex distribution. I have already updated anything without success.

• Error “Missing = inserted for ifnum”: suggests that it is an issue with how the user was using pgfmath functions in tikz package. In my MWE I am not using tikz directly (to my knowledge) and issue persists.

MWE

Below is a minimum working example that replicates the issue. I use input a lot to keep separate files clean and have replicated that structure here in case that is somehow related. All of the separate files are in the same folder.

In draft_paper.tex

listfiles

documentclass[sort&compress]{cas-dc} 

input{settings_options_parameters} % contains all of the settings/options that I don't think we'll need to change very often

begin{document}

input{frontmatter} 

end{document}

In settings_options_parameters.tex

usepackage{natbib}
usepackage{lipsum}  

ExplSyntaxOn
keys_set:nn { stm / mktitle } { nologo }
ExplSyntaxOff

In frontmatter.tex

Based heavily on the documentation for cas-dc here.

title[mode=title]{Test Title: 101 Reasons Why I Can't LaTeX}

tnotemark[1]

tnotetext[1]{This document is the result of blood, sweat, tears and taxpayer money.}

author[1]{Dummy Author One}[%
    type=author,
    orcid=]
cormark[1]
fnmark[1]
ead[url]{[email protected], url{fakewebaddress.com}}
credit{Everything}
address[1]{Nowheresville, North America}


author[1]{Dummy Author Two}[%
    type=author,
    orcid=]
cormark[2]
fnmark[2]
ead[url]{[email protected], url{phishingsupplies.com}}
credit{Nothing}


author[1]{Dummy Author Two}[%
    type=author,
    orcid=]
cormark[1,2]
fnmark[1,2]
ead[url]{[email protected], url{hackingsupplies.com}}
credit{Nothing}
address[1]{Nowheresville, North America}

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


% Abstract
begin{abstract}[SUMMARY]
lipsum[1-1]
end{abstract}

% Key words
begin{keywords}
LaTeX sep Science sep Crying
end{keywords}

maketitle

Results

These are images of the end result, the first time it compiles, the second time it throws the error mentioned above and it never shows the title notes tnotemark or author notes cormark

The log file after the error is thrown can be found here. listfiles has been added, but if anything else should be added please let me know.

Many thanks for any help on this issue!

ExplSyntaxOn
makeatletter
RenewDocumentCommand process@marks { }
   {
     bool_lazy_or:nnTF
         { cs_if_free_p:c { mark@corautheauthor } }
         { tl_if_empty_p:c { mark@corautheauthor } }
       { ignorespaces }
       { str_set:Nx l_tmpa_str { use:c{ mark@corautheauthor } }
         clist_map_inline:Nn l_tmpa_str
           {
             int_case:nn { ##1 }
               {
                 { 1 } { sep$ast$ }
                 { 2 } { sep$astast$ }
                 { 3 } { sep$ast!ast!ast$ }
               }
               tex_def:D sep{unskip,}
           }
         }
      cs_if_free:cTF { mark@fnautheauthor }
        { ignorespaces }
        { sepuse:c { mark@fnautheauthor }
          tex_def:D sep{unskip,}
        }
      }
makeatother
ExplSyntaxOff

author[1]{Dummy Author Two}
ead{[email protected]} % e-mail adrress
ead[mashed potatoes]{hackingsupplies.com} % website