Hi,
I think I have the same problem but in this case Dolphin is not starting. It gives the following error
dolphin: symbol lookup error: /usr/lib/x86_64-linux-gnu/libKF5NewStuff.so.5: undefined symbol: _ZN7KNSCore6Engine15signalErrorCodeERKNS_9ErrorCodeERK7QStringRK8QVariant
It all started since the update of libkf5newstuff5:amd64 5.51.0-1 -> 5.54.0-1 .
Regards.
Ariel