Missing Icons in gui - Mint Mate 19, Luminance HDR 2.5.1

I’m running Linux Mint Mate 19, with the Mint-Y-Dark theme.

Currently installed version of Luminance HDR is 2.5.1 dhor:myway ppa. It seems to run OK, however there are some gui icons missing, as in the attached images below. Nothing major, just on the buttons to add / remove images or import / export tone mapping settings.

Has anyone else experienced this? Or is this an issue with my Mint install? Seems to be the same no matter what theme I use for Mate.

Thanks,

Brian

Well, thats interesting.

I’m running Mint 19 Mate Edition, and if I do this on the command line before launching Luminance-HDR:

export QT_QPA_PLATFORMTHEME=gtk3

The missing icons appear! I can’t remember where saw that command, it seemed to be on a page discussing missing icons on kdenlive or something…

So perhaps an issue with gtk3 on Mint Mate 19?