Hi,
First time to use Kdenlive and I ran into this issue. When I want to add a clip, say a jpg or png, I click add ann find the correct folder and instead of seeing thumbnails I see only a list of image names. Being as I have hundreds sequentially numbered in long date format, that becomes a nightmare to find the right image. I tried dragging from Nautilus direct into the files section, but was not able to drag.

Is there a setting somewhere to either enable dragging, or thumbnails please.

I see there is no thumbnail preview. You can drag/drop the any file from a folder to the project bin and from there onto the timeline.
Indeed: Thumbnail preview for adding clips would be a nice feature.