You use wrong syntax for multirow
cells. Missed are *
or width of cells. For example: correct syntax is \multirow{2}{*}{B1}
, not \multirow{2}{}{B1}
etc. Complete MWE:
\documentclass{article}
\usepackage{longtable, makecell, multirow}
\renewcommand\theadfont{\small\bfseries}
\renewcommand\theadgape{}
\title{Test}
\begin{document}
\begin{longtable}{|l|l|l|l|l|}
\hline
\thead{Sensor} & \thead{Erfassung} & \thead{Typ}
& \thead{Spule} & \thead{Erfassendes Steuerger\"{a}t} \\
\hline
B13.1 & Testwelle & Induktiv
& -- & ESO9 + CRA \\
\hline
B13.2 & Testwelle & Induktiv
& -- & ESO9 + MSI6 \\
\hline
\multirow{2}{*}{B1} & \multirow{2}{*}{Testwelle} & \multirow{2}{5em}{Induktiv Doppelspule}
& 1 & ESO9 + CRA \\
\cline{4-5}
& & & 2 & MSI6 \\
\hline
\end{longtable}
\label{tab:table1} % <--- wrong position!
\end{document}

Note: \label
for table should be inside or after the caption, and caption has ti be located inside the table
or longtable
environment. Since you are not providing any information from which will be clear are you really need longtable
, maybe you need to add to your table the following preamble:
\begin{longtable}{|l|l|l|l|l|}
\caption{My long table}
\label{tab:table1} \\
\hline
\thead{Sensor} & \thead{Erfassung} & \thead{Typ}
& \thead{Spule} & \thead{Erfassendes Steuerger\"{a}t} \\
\hline
\endfirsthead
\caption[]{My long table (cont.)} \\
\hline
\thead{Sensor} & \thead{Erfassung} & \thead{Typ}
& \thead{Spule} & \thead{Erfassendes Steuerger\"{a}t} \\
\hline
\thead{Sensor} & \thead{Erfassung} & \thead{Typ}
& \thead{Spule} & \thead{Erfassendes Steuerger\"{a}t} \\
\hline
\endhead
\hline
\multicolumn{5}{r}{\footnotesize\textit{Continue on the next page}}
\endfoot
\hline
\endlastfoot
% table body
Using longtable
, you need to compile your document at least two times, before the table line up correctly.