I compile the following source without any problem:
Code: Select all
\documentclass[12pt,titlepage]{report}
%\usepackage{ucs} % unicode support
%\usepackage[utf8x]{inputenc}
%\usepackage[english,hebrew]{babel}
\usepackage[mathscr]{euscript}
\usepackage{mathrsfs}
\usepackage{mathtools, amsmath,amsthm, amssymb,latexsym,amsfonts}
\newtheorem{theorem}{Theorem}[chapter]
\begin{document}
\begin{theorem}
kkkkk
\end{theorem}
\end{document}