！缺少}插入。} \end{thebibliography}

Question

我不断收到此错误。即使第 132 行没有任何缺失或额外内容。我也检查了类似的错误，但找不到适合我的正确解决方案。

错误：

! Missing } inserted.
<inserted text>
}
l.132 \end{thebibliography}
I've inserted something that you may have forgotten.
(See the <inserted text> above.)
With luck, this will get me unwedged. But if you
really didn't forget anything, try typing `2' now; then
my insertion and my current dilemma will both disappear.

代码片段：

\begin{figure}[h] 
\centering
\includegraphics[scale=0.5]{210}
\caption{{\small Schematic}}
\label{fig:210}                   % 132 line
\end{figure}