I use eqnarray for equations. After using csvreader, the "special" mathematical symbols like "sum" disappear.

The following is the code. The equation before and after csvreader is the same.

    \begin{eqnarray}
0 & = & \sum_{t=1}^{n} (E_{t} - A_{t}) * (1+r)^{-t} + L_{n} (1+r)^{-n} - A_{0}
\end{eqnarray}

\begin{table}[h]
\begin{minipage}{\linewidth}
\renewcommand{\footnoterule}{}
\resizebox{\textwidth}{!}{%
table head=\hline& Jan & Feb & Mrz & Apr & Mai & Jun & Jul & Aug & Sep & Okt & Nov & Dez & Summe\\\hline\hline,
late after line=\\\hline]%
{DATA/KVN/kvnmonat.csv}{artikel=\artikel,1=\jan,2=\feb,3=\mrz,4=\apr,5=\mai,6=\jun,7=\jul,8=\aug,9=\sep,10=\okt,11=\nov,12=\dez,Summe=\sum}%
{\artikel&\jan&\feb&\mrz&\apr&\mai&\jun&\jul&\aug&\sep&\okt&\nov&\dez&\sum}%
}
\caption[Anzahl der bei KVN gebauten Displays]
{\label{tab:kvndisplaykomm} Menge der bei KVN gebauten Displays unterteilt nach Monaten und Display.}
\end{minipage}
\end{table}

\begin{eqnarray}
0 & = & \sum_{t=1}^{n} (E_{t} - A_{t}) * (1+r)^{-t} + L_{n} (1+r)^{-n} - A_{0}
\end{eqnarray}


After Compiling it looks like this:

The Sum-Symbol is missing from now on in the whole document, in all chapters.

Can anyone help me? Thank you!

• Welcome to TeX.SX! Maybe change Summe=\sum to Summe=\summe and change the table accordingly? – TeXnician Apr 22 '18 at 17:02
• Welcome to TeX SX! I use eqnarray for equations. Well, you shouldn't, see Avoid eqnarray. This being said, could you post a full compilable code? – Bernard Apr 22 '18 at 17:02
• @TeXnician that was great work man! Thank you. Now it works. That was the problem. I wasn´t even aware of my usage of the same variable. Thank you, Sir! – Jonas Müller Apr 22 '18 at 17:08

If you have a look at your assignments you will notice that you use \sum:
{artikel=\artikel,1=\jan,2=\feb,3=\mrz,4=\apr,5=\mai,6=\jun,7=\jul,8=\aug,9=\sep,10=\okt,11=\nov,12=\dez,Summe=\sum}

This overwrites the \sum macro with every item read. Hence \sum will not work in math mode (at least not the way you expect it to work).
Just a comment: You should not use eqnarray for equations, because it is obsolete.
• Yes, for internal reasons, csvsimple does global assignments to the variables; it's better to use uncommon names, for instance with all capital letters. – egreg Apr 22 '18 at 21:37