File cannot be found error

Question

Can't find a pdf file of the document anymore, pdf does not compile, after entering the following

\documentclass[a4paper, 
    pointlessnumbers, 
    %draft,
    parskip=half,
    automark
        ]{scrartcl}
\setlength{\parindent}{0pt}
\usepackage[a4paper, left=2.2cm, right=2.2cm, top=2.5cm, bottom=2.5cm,]{geometry}
\usepackage{scrpage2}
\clearscrheadfoot
\pagestyle{scrheadings}
\usepackage[ngerman]{babel}
\usepackage[pdftex]{graphicx,color}
\usepackage[utf8]{inputenc}
\usepackage{amssymb,amsmath,amsthm, amsfonts} 
\usepackage{latexsym}
\usepackage[decimalsymbol=comma]{siunitx}
\usepackage{booktabs}
\usepackage{tabulary}
\usepackage[dvipsnames]{xcolor} 
\usepackage[centerlast,small,sc]{caption}
\usepackage{here}
\usepackage{siunitx}
\usepackage{titling}
\usepackage{subfigure}
\usepackage{hyperref}
\renewcommand{\i}{\mathrm{i}}
\newcommand{\e}{\mathrm{e}}
\newcommand{\diff}{\mathrm{d}}
\newcommand{\figref}[1]{Abb. \ref{#1}} 

\newcommand{\ImNew}{\operatorname{Im}}
\newcommand{\ReNew}{\operatorname{Re}}

\newcommand{\xdot}{\cdot}
\newcommand{\funof}[1]{{\color{gray}(#1)}}


%Titelseite
\title{m}
\author{b}
%Dokument
\begin{document}
\setcounter{page}{0}
\maketitle
\thispagestyle{empty} % Keine Seitenzahl auf Titelseite
\ofoot{\upshape\thepage}
\clearpage
%Inhaltsverzeichnis
%\thispagestyle{empty}
\tableofcontents
\clearpage
%Hauptdokument
\pagenumbering{arabic}
\ihead{\upshape\scriptsize \leftmark}
\ohead{\upshape\scriptsize \thetitle}
%\ifoot{\upshape \scriptsize}
\ofoot{\upshape\thepage}
\begin{equation}
tan\phi=\frac{{\frac{1}{\omega L_M}+\frac{\omega L_{\sigma}\gamma^2 I_2^2}{U_1^2}}{\frac{1}{R_{FE}}+
+\frac{\sqrt{\frac{U_1^2}{\gamma^2 I_2^2}-\omega^2  L_{\sigma}^2}\gamma^2 I_2^2}{U_1^2}}
\label{eq:80}
\end{equation}
Dies ist äquivalent zu
\begin{equation}
\phi=arctan(Gl.\ref{eq:80})
\label{eq:5}
\end{equation}

?ab hier eigene Werte eingeben:
In dem Fall ist\
A=$\omega L_M=2\pi f L_M=2\pi$
\end{document}

Answer 1

Your document has several errors that you need to address in order for it to compile.

1. Replace deprecated scrpage2 package

The scrpage2 package referenced in the preamble (\usepackage{scrpage2}) has been deprecated and should be replaced with \usepackage{scrlayer-scrpage}. According to the package documentation:

The package is deprecated and should not be used any longer. You can very easily replace it by the KOMA -Script package scrlayer-scrpage that is documented in the English and the German KOMA -Script guide.

This question has additional advice on replacing the scrpage2 package: LaTeX Error: File `scrpage2.sty' not found

2. Use \sisetup instead of siunitx to control decimal style

[decimalsymbol=comma] is not a valid option for siunitx. To change the decimal style, use the \sisteup command: Comma as decimal marker with siunitx (Spanish usage)

You also import siunitx more than once, so you should delete the extra reference and just have \usepackage{siunitx} followed by the appropriate \sisetup command.

3. Use correct number of braces in equations

The equation labeled 80 doesn't have enough braces to properly enclose the equation. There's a lot going on so I'm honestly not sure what you are trying to do there, but one way to troubleshoot is to break each set of braces into separate indented lines so you can confirm each term is correctly enclosed. In particular I would check that each fraction has two sets of braces (\frac{}{}) and that the terms under the radical are enclosed (\sqrt{}).