Fandol fonts not rendered in TeXworks PDF viewer

Question

I am using TeXworks bundled in the MiKTeX distribution and the Fan­dol Simplified Chinese font family (available in TeX Live and MiKTeX). However, the Fan­dol font is not rendered in the TeXworks PDF viewer.

My OS is Windows 8 and the newest(-ish) version of poppler-data is present:

On the other hand, Adobe Acrobat Reader DC is able to render the generated PDF file.

Here is the MWE:

% !TeX program = XeLaTeX
\documentclass{article}
\usepackage{fontspec}
\setmainfont{FandolSong-Regular}
\begin{document}
\textsf{English} English 中文 English \textsf{English}
\end{document}

and here are the log file contents

This is XeTeX, Version 3.14159265-2.6-0.99999 (MiKTeX 2.9.6840 64-bit) (preloaded format=xelatex 2018.10.24) ...
entering extended mode
**./FandolTest.tex
(FandolTest.tex
LaTeX2e <2018-04-01> patch level 5
("C:\Program Files\MiKTeX 2.9\tex\latex\base\article.cls"
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
("C:\Program Files\MiKTeX 2.9\tex\latex\base\size10.clo"
File: size10.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
)
...
% Irrelevant information regarding counters and dimensions
...
("C:\Program Files\MiKTeX 2.9\tex\latex\fontspec\fontspec.sty"
("C:\Program Files\MiKTeX 2.9\tex\latex\l3packages\xparse\xparse.sty"
("C:\Program Files\MiKTeX 2.9\tex\latex\l3kernel\expl3.sty"
Package: expl3 2018-10-19 L3 programming layer (loader) 

("C:\Program Files\MiKTeX 2.9\tex\latex\l3kernel\expl3-code.tex"
Package: expl3 2018-10-19 L3 programming layer (code)
...
% Irrelevant information regarding counters, dimensions, skips and boxes
...
Package: fontspec 2018/07/30 vv2.6h Font selection for XeLaTeX and LuaLaTeX

("C:\Program Files\MiKTeX 2.9\tex\latex\fontspec\fontspec-xetex.sty"
Package: fontspec-xetex 2018/07/30 vv2.6h Font selection for XeLaTeX and LuaLaT
eX
...
% Irrelevant information regarding counters and dimensions
...

("C:\Program Files\MiKTeX 2.9\tex\latex\base\fontenc.sty"
Package: fontenc 2017/04/05 v2.0i Standard LaTeX package

("C:\Program Files\MiKTeX 2.9\tex\latex\base\tuenc.def"
File: tuenc.def 2017/04/05 v2.0i Standard LaTeX file
LaTeX Font Info:    Redeclaring font encoding TU on input line 82.
))
("C:\Program Files\MiKTeX 2.9\tex\latex\fontspec\fontspec.cfg")
LaTeX Info: Redefining \itshape on input line 3910.
LaTeX Info: Redefining \slshape on input line 3915.
LaTeX Info: Redefining \scshape on input line 3920.
LaTeX Info: Redefining \upshape on input line 3925.
LaTeX Info: Redefining \em on input line 3955.
LaTeX Info: Redefining \emph on input line 3980.
LaTeX Info: Redefining \- on input line 4034.
))

Package fontspec Info: Font "FandolSong-Regular" does not contain any OpenType
(fontspec)             `Script' information.


Package fontspec Info: Could not resolve font "FandolSong-Regular/I" (it
(fontspec)             probably doesn't exist).


Package fontspec Info: Font family 'FandolSong-Regular(0)' created for font
(fontspec)             'FandolSong-Regular' with options [Ligatures=TeX].
(fontspec)              
(fontspec)              This font family consists of the following NFSS
(fontspec)             series/shapes:
(fontspec)              
(fontspec)             - 'normal' (m/n) with NFSS spec.:
(fontspec)             <->"FandolSong-Regular/OT:mapping=tex-text;"
(fontspec)             - 'small caps'  (m/sc) with NFSS spec.: 
(fontspec)             - 'bold' (bx/n) with NFSS spec.:
(fontspec)             <->"FandolSong-Regular/B/OT:mapping=tex-text;"
(fontspec)             - 'bold small caps'  (bx/sc) with NFSS spec.: 
(fontspec)             - 'bold italic' (bx/it) with NFSS spec.:
(fontspec)             <->"FandolSong-Regular/BI/OT:mapping=tex-text;"
(fontspec)             - 'bold italic small caps'  (bx/itsc) with NFSS spec.: 

LaTeX Info: Redefining \rmfamily on input line 5.

(FandolTest.aux)
\openout1 = `FandolTest.aux'.
...
% Irrelevant information regarding math font setup
...
Here is how much of TeX's memory you used:
 11269 strings out of 427792
 249161 string characters out of 3151723
 315042 words of memory out of 3000000
 15305 multiletter control sequences out of 15000+200000
 532402 words of font info for 32 fonts, out of 3000000 for 9000
 1328 hyphenation exceptions out of 8191
 39i,4n,67p,355b,443s stack positions out of 5000i,500n,10000p,200000b,50000s

Output written on FandolTest.pdf (1 page).

Answer 1

There appears to be a difference in the way MiKTeX compiles the inbuilt copy of TeXworks versus the Standard release and TeX Live copies although they all use the same version of source code they each tend to use different QT versions for graphics engine.

In this case I recommend that unless you have other reasons for switching editor or viewer (I would suggest you can replace the internal viewer with say SumatraPDF as a good solution to this bug) that you temporarily use the Standalone version of TeXworks until MiKTeX address the viewer fonts issue.

For compatibility with other users I suggest the 0.6.2 version from the main release page https://github.com/TeXworks/texworks/releases

Personally I would use and reconfigure the zip (portable version) since it would be easier to delete once the MiKTeX version is updated, however that requires you add the "settings" that MiKTeX needs to the Typesetting preferences (you can cut and paste entries from one to the other) The alternative is to use the installer setup and let it do most of the work then just check between the two for any minor differences.