QFontEngine: Glyph neither outline nor bitmap format=0

[Mr Li]

system: centos7 . I want to convert html to picture.
yum install wkhtmltopdf

and then:
wkhtmltoimage 'http://127.0.0.1:100/convert_img/?path=/home/1/json&picName=1079_pic6' hello.jpg

it`s erro:
Loading page (1/2)
load glyph failed err=24 face=0x3a473b0, glyph=0 ] 42%
QFontEngine: Glyph neither outline nor bitmap format=0
load glyph failed err=24 face=0x3a473b0, glyph=3
QFontEngine: Glyph neither outline nor bitmap format=0
Floating point exception (core dumped)

so what should i do?????