\usepackage[]{bookmark}
\addto\@part{\def\bookmarksetup{bold}}
\addto\@chapter{\def\bookmarksetup{bold}}
\addto\@section{\def\bookmarksetup{bold}}
\addto\@paragraph{\def\bookmarksetup{bold}}
\addto\@printindex{\def\bookmarksetup{bold,color=red165}}
\addto\@tableofcontent{\def\bookmarksetup{bold,color=red165}}
Подозреваю, что ругань у вас на символ @. Попробуйте так:
\makeatletter
\addto\@part{\def\bookmarksetup{bold}}
\addto\@chapter{\def\bookmarksetup{bold}}
\addto\@section{\def\bookmarksetup{bold}}
\addto\@paragraph{\def\bookmarksetup{bold}}
\addto\@printindex{\def\bookmarksetup{bold,color=red165}}
\addto\@tableofcontent{\def\bookmarksetup{bold,color=red165}}
\makeatother
С уважением, Ник.