xltaular gives issue for 2 columns

[payalsingla2102]

begin{xltabular}[c]{\linewidth}{@{} X @{}}

\caption{tabels} \label{pe} \

\hline \multicolumn{1}{c}{\textbf{Sy}} & \multicolumn{1}{c}{\textbf{S}} \ \hline
\endfirsthead

\multicolumn{3}{l}
{\textit{continued from previous page}} \

\hline \multicolumn{1}{c}{\textbf{Study}} & \multicolumn{1}{c}{\textbf{Software Used}} \ \hline
\endhead

\hline \multicolumn{3}{r}{\textit{Continued on next page}} \
\endfoot

\hline
\endlastfoot

\cite{xen}& some useful textt\

\end{xltabular}

gives the error Extra alignment tab has been changed to \cr.

‪./literature_survey.tex, 195‬
You have written too many alignment tabs in a table, causing one of them to be turned into a line break. Make sure you have specified the correct number of columns in your table.
Learn more
\endtemplate

l.195 \end{xltabular}, but the number of column seems fine

[rolfn]

Please provide a complete sample document and not just an excerpt. The source code should also be formatted sensibly using code segment markup syntax as follows:

```latex
\documentclass{article}
\usepackage{xltabular}

\begin{document}
...
\end{document}
```

[hvoss49]

You have

begin{xltabular}[c]{\linewidth}{@{} X @{}}
\caption{tabels} \label{pe} \\

which defines one column! But then you used

\multicolumn{1}{c}{\textbf{Sy}} & \multicolumn{1}{c}{\textbf{S}} \ \hline

a line with two columns ...

However, as Rolf already wrote: Provide a complete example ...