Thanks for quick reply.Now I  find the mems-studio.desktop file under /usr/share/applications/  and all different size of mems-studio.png  under /usr/share/icons/hicolor/dddxddd/  .cat /usr/share/applications/mems-studio.desktop  shows[Desktop Entry]...

I have the same problem with mems-studio Version 1.3.0 on Lubuntu 24.04.The solution fixed the problem, and it seems for me that "QT_QPA_PLATFORMTHEME=gtk3" does the fix.As I had mentioned that I use Lubuntu 24.04 and the QT_QPA_PLATFORMTHEME environ...

I had the same problem with Cube IDE 1.16.1 installation on Lubuntu 24.04 , the lightweight version of desktop Ubuntu 24.04.By apply the Generic Linux installation, it seems went success. Basically the installation went to /opt/st/stm32cubeide_1.16.1...