According to customer adding fonts from resources crashes, but loading from filesystem works.
In my case any addApplicationFont or addApplicationFontFromData were crashing.
It fails by registering the font using the QPA fontdatabase.
Qt 5.5 was used from the binary release which has been configured to use fontconfig.
It works if Qt is configured without fontconfig and according the customer it was working with Qt 5.4.
Please check the attached code for reproduction, I have been using imx6 device for that.