Document does not render with table

Question

\begin{table}[htbp]
\centering
\caption{Zusammensetzung der Proben}
    \begin{tabular}{cccc}
        \toprule
    \multirow{2}{*}{Probe} &  [TRA-Puffer 2.5$\frac{\text{mg}}{\text{ml}}$ Lipase] & [Gummi-Arabicum-Lösung] & [Speiseöl]\\
    & = \si{\ml} & = \si{\ml} & = \si{\ml} \\
\midrule
1 & 5 & 20 & 0.03 \\
  \bottomrule
\end{tabular}%
  \label{tab:Zusammensetzung}%
\end{table}%

this renders just fine

\begin{table}[htbp]
\centering
\caption{Zusammensetzung der Proben}
\begin{tabular}{ccc}
        \toprule
[TRA-Puffer 2.5$\frac{\text{mg}}{\text{ml}}$ Lipase] & [Gummi-Arabicum-Lösung] & [Speiseöl]\\
     = \si{\ml} & = \si{\ml} & = \si{\ml} \\
\midrule
 5 & 20 & 0.03 \\
  \bottomrule
\end{tabular}%
  \label{tab:Zusammensetzung}%
\end{table}%

with this code I'm stuck at rendering the .tex that contains this table. Any ideas why?

Answer 1

Enclose the expression inside square brackets using braces to prevent it from being taken as an optional argument for a line changing command:

\documentclass{article}
\usepackage{booktabs,siunitx}

\begin{document}

\begin{table}[htbp]
\centering
\caption{Zusammensetzung der Proben}
\begin{tabular}{ccc}
        \toprule
{[TRA-Puffer 2.5$\frac{\text{mg}}{\text{ml}}$ Lipase]} & [Gummi-Arabicum-Lösung] & [Speiseöl]\\
     = \si{\ml} & = \si{\ml} & = \si{\ml} \\
\midrule
 5 & 20 & 0.03 \\
  \bottomrule
\end{tabular}%
  \label{tab:Zusammensetzung}%
\end{table}%
\end{document}