# Fontspec doesn't find Tex Gyre Pagella Italic

I'm using XeLaTeX and when calling

I get the message

Requested font "TeX Gyre Pagella Italic" at 11.99997pt -> font not found, using "nullfont"
! Package fontspec Error: The font "TeX Gyre Pagella Italic" cannot be found.

I can see that Windows 10 lists the font as installed, I have the current versions of packages fontspec, libertine, and I refreshed the font map with the MikTeX Console, but it still seems to not be able to find the font.

Below is MWE:

\documentclass[english,a4paper,12pt]{article}
\usepackage{libertine}
\usepackage[bold-style=ISO]{unicode-math}
\begin{document}
XX
\end{document}

The Pagella family uses "TeX Gyre Pagella" as family name. The italic shape is called "TeXGyrePagella-Italic". In addition, you are not setting a font family but a single font, so it makes more sense to use \newfontface. Overall, the following works for me using TeXLive 2019 on Debian Linux:

\documentclass[english,a4paper,12pt]{article}
\usepackage[bold-style=ISO]{unicode-math}
\begin{document}
\end{document}

The problem is, that xelatex dosen't find the font by name. To fix that, you have to specify the font file:

\documentclass[a4paper,12pt]{article}
\usepackage{libertine}
\usepackage[bold-style=ISO]{unicode-math}
\begin{document}
\end{document}

If you run pdffonts you can see, that the right font is used:

name                                     type              encoding         emb sub uni object ID
---------------------------------------- ----------------- ---------------- --- --- --- ---------
SLTSXB+TeXGyrePagella-Italic-Identity-H  CID Type 0C       Identity-H       yes yes yes      5  0
LJPSEU+LinLibertineO-Identity-H          CID Type 0C       Identity-H       yes yes yes      7  0

You can try