Nabla symbol and underbrace show only black dot

Question

I'm using MikTex on Windows 10.

I wanted to write the following equation:

\underbrace{\frac{\partial\rho\phi }{\partial t}}+\underbrace{\nabla\cdot 
(\rho u \phi)}-\underbrace{\nabla\cdot (\rho \nabla\phi)}=\underbrace{S}

What i am getting is:

These are the packages I am using:

\usepackage{hyph}
\usepackage{lscape}
\usepackage[T1]{fontenc}
% Naturwissenschaftliche Bibliographien
\usepackage[square, comma, numbers, sort&compress]{natbib}
\usepackage[utf8]{inputenc} % geändert auf utf8
\usepackage{fancyhdr}
\usepackage[dvips]{graphicx}
\usepackage{color}
\usepackage{longtable}
\usepackage{supertabular}
\usepackage{svg}
\usepackage{dashrule}
\usepackage{tabularx}
\usepackage{lscape}
\usepackage{slashbox}
\usepackage{pict2e}
\usepackage{afterpage}% \afterpage{\clearpage} um float-Speicher zurückzusetzten
\usepackage[onehalfspacing]{setspace} % Veränderung des Zeilenabstands
\usepackage{latexsym}
\usepackage{float,rotating}
\usepackage{caption}
\captionsetup[table]{position=above}
\captionsetup[figure]{position=below}
\captionsetup{format=hang, labelformat=simple, labelsep=colon, justification=raggedright, singlelinecheck=off, labelfont=bf, textfont=normalfont}
%Fremdsprachen
%------------------------
\usepackage[ngerman]{babel}
\usepackage[babel, german=quotes]{csquotes}
\usepackage{textcomp}
%Abbildungen
%------------------------
\usepackage{subfig}
\usepackage{booktabs}
\usepackage{epstopdf}
%
%Formeln und Gleichungen
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{enumerate}
\usepackage{remreset}
\usepackage{stmaryrd} %definiert u.a. \minuso als Symbol für Standardbedingungen
\usepackage{dcolumn}
\usepackage{multirow}
\usepackage{fdsymbol}  
\usepackage{hyperref} 
\usepackage{pgfplots} 
%SI-Units
\usepackage{siunitx}

Can anyone help me out where the problem is?

Best regards,

Gesetzt

Answer 1

The problem lies to fdsymbol package. At page 19 of package documentation is stated that nabla symbol and others are missing. Imho you should try to use another symbol package or take a look at this question. I would also recommend, if there is no other need to choose one of the math fonts stated here.