kdenlive previews are dull green

i'm 50/50 sure this is a sdl1/sdl2 mismatch between kdenlive and melt (both are projects i hadn't heard of 4 hours ago) i'm using kdenlive. the two previews (clip and project) are both a dull green colour ... so ... so i guess they're not getting any data? amongst a sea of log messages, i see this gem which makes me think OpenGL or SDL isn't talking to itself ...

QQmlContext: Cannot set context object on invalid context.
QQmlComponent: Cannot create a component in an invalid context
QQmlContext: Cannot set context object on invalid context.
QQmlComponent: Cannot create a component in an invalid context

i've tried running in software ...

QT_QUICK_BACKEND=software kdenlive

... but that doesn't seem to fixit. - raspberry pi 5 / os in 2024-11-19 - kdenlive 22.12.3 - mlt 7.12.0 - OpenGL 3.1 So ... does anyone know how to get those kdenlive previews working?