Cfrgtkky

Including an appendix chapter using include{chapter_appendixA} results in a 'weird error' in overleaf (compiling with XeLaTeX):

! Missing number, treated as zero.

p
l.1 chapter{chapter_appendixA}
A number should have been here; I inserted `0'.

! Package PGF Math Error: Unknown function `A' (in '-A*LabelSize ').
See the PGF Math package documentation for explanation.
Type H for immediate help.

The chapter_appendixA.tex file only includes the following:

chapter{Appendix}

Some text

Other appendix examples do not include a number there. The error arises when activating the gray chapter label boxes using AddLabels from "Show current chapter number on each page margin"
Does anyone have an idea?

My main code is the following:

documentclass[10pt,twoside,parskip=half,table,xcdraw]{scrbook}

usepackage[

  paperwidth=170mm,

  paperheight=240mm,

  top=2.5cm,

  bottom=3cm,

  inner=30mm,

  outer=25mm,

  heightrounded=true

]{geometry}



input{preamble.tex}



raggedbottom



% avoid annoying errors when using Koma-Script with bibtex

DeclareOldFontCommand{bf}{normalfontbfseries}{mathbf}





begin{document}



%%%%%%%%%%%%%%%%%%

%% FRONT MATTER %%

%%%%%%%%%%%%%%%%%%



frontmatter

tableofcontents



%%%%%%%%%%%%%%%%%

%% MAIN MATTER %%

%%%%%%%%%%%%%%%%%



mainmatter

rehead{small{Chapter thechapter}}



chapter{A chapter}

    Some text

AddLabels  



%%%%%%%%%%%%%%

%% APPENDIX %%

%%%%%%%%%%%%%%



appendix

include{chapter_appendixA}



end{document}

With accompanyingpreamble.tex:

%%%%%%%%%%%

%% FONTS %%

%%%%%%%%%%%

usepackage{xcolor}

usepackage{libertine}

setmainfont{Linux Libertine O} 

setsansfont{Linux Biolinum O}



%Set chapter titles and numbering

usepackage[headsepline=true]{scrlayer-scrpage}

clearpairofpagestyles





%%%%%%%%%%%%%%%%%%%%%%%

%% chapter numbering %%

%%%%%%%%%%%%%%%%%%%%%%%



%renewcommand*{thesection}{thechapter.arabic{section}}

renewcommand{sectionmark}[1]{markright{#1}{}}



% Create header for odd (o) and even (e) pages

lehead{thepage}rohead{thepage}

lohead{{smallrightmark}}

setkomafont{pagehead}{normalfontnormalcolor}



usepackage[times]{quotchap}   % fancy chapter beginning



pretolerance=10000

tolerance=10000



% Gray boxes for chapter numbering on pages

usepackage[contents={},opacity=1,scale=1,color=white]{background}

usepackage{tikzpagenodes}

usepackage{totcount}

usetikzlibrary{calc}



newififMaterial



newlengthLabelSize

setlengthLabelSize{2.5cm}

AtBeginDocument{%

regtotcounter{chapter}

%setlengthLabelSize{dimexprtextheight/totvalue{chapter}relax}

ifdimLabelSize>2.5cmrelax

  globalsetlengthLabelSize{2.5cm}

fi}



newcommandAddLabels{%

    Materialtrue%

    AddEverypageHook{%

        ifMaterial%

        ifoddvalue{page} %

        backgroundsetup{

          angle=90, position={current page.east|-current page text area.north  east}, vshift=8pt, hshift=-thechapter*LabelSize,

          contents={%

          tikznode[fill=gray!30,anchor=west,text width=LabelSize,

            align=center,text height=15pt,text depth=10pt,font=largesffamily] {thechapter};  }%

        }

         else

         backgroundsetup{

          angle=90, position={current page.west|-current page text area.north west}, vshift=-8pt, hshift=-thechapter*LabelSize,

          contents={%

          tikznode[fill=gray!30,anchor=west,text width=LabelSize,

            align=center,text height=15pt,text depth=10pt,font=largesffamily] {thechapter}; }%

         }

     fi

     BgMaterial%

     elserelaxfi}%

}



newcommandRemoveLabels{Materialfalse}

usepackage{afterpage}

newcommandRemoveThisLabel{%

    Materialfalse

    afterpage{globalMaterialtrue}%

}

KOMA-Script has a more robust approach to adding chapter thumbs using its scrlayer-scrpage package. Download the examples from the KOMA-Script book, and use the files in the Anhang-B folder. Here is a translated version of the example with an appendix added, which will work if the chapterthumb.sty file from the examples is in the same folder:

documentclass{scrbook}

usepackage{chapterthumb}

usepackage{scrlayer-scrpage}

AddLayersToPageStyle{@everystyle@}{chapterthumb}

addtokomafont{chapterthumb}{bfseries}



begin{document}

chapter{In the beginning it starts}dots

chapter{continuing}dots

chapter{further}dots

chapter{and even further}dots

chapter{And always on}dots

chapter{Goes the journey}dots

chapter{out}dots

chapter{And further out}dots

chapter{Always further out}dots



appendix



chapter{Until the end}dots



end{document}

If you wish to customize it, this has been addressed several times before; see the chapterthumb tag.