Plasma shows themes, etc. as installed, though they are not and vice versa
Running Kubuntu 17.04.
When I try to get new desktop themes, etc. there is a mismatch between what system settings show and what get new things dialog shows. The get new things dialog shows several themes as ‘installed’. But they are not. I remember installing some of them earlier and removing them later.
How do I remove this mismatch?