TeX capacity memory exceeded error

Question

\caption[$Set\:3$: Intermediate set]{$Set\:3$: Intermediate set; Classical orifice plate ($s3c$); Plate numbers ($s3f(0-3)$); Classical plate,($s3p$).}

Is this a wrong caption? Because it is prompting an error as follows pointing at the line number of this caption:

Tex capacity exceeded, sorry [main memory size 1500000].

Answer 1

I build a minimal example with your fragment. It works fine whether I load hyperref or not.

\documentclass{article}
\usepackage{hyperref}
\begin{document}
\listoffigures
\begin{figure}[!ht]
\caption[$Set\:3$: Intermediate set]{$Set\:3$: Intermediate set; Classical orifice plate ($s3c$); Plate numbers ($s3f(0-3)$); Classical plate,($s3p$).}
\end{figure}
\end{document}

Small tip: you can't use math expression in bookmarks. You will get the warning:

Token not allowed in a PDF string

To avoid this use:

\texorpdfstring{<expression in text>}{<expression in bookmark>}