I'm running a recently installed Kdenlive Version 17.04.3, on a PC running Ubuntu Mate 17.04 (incorporating Mate Desktop Environment 1.18.0). 

Kdenlive was installed yesterday via the official ppa: (sudo add-apt-repository ppa:kdenlive/kdenlive-stable)

I am able to add clips to a yet-unnamed project through the Project > Add Clip menu choice. In implementing this command, I am able to view all the folders on my Ubuntu system, and successfully import a clip for editing. 

However, other commands that also require system drive and folder access fail to work. For example, the File > Open command opens a white box -- but does not show all the individual folders on my system (although it shows some of the drives at left). If I try to click on an individual drive, it just hangs - but does not display the folders in the drive. I am, however, still able to close the box through the "Cancel" button at the bottom. 

The File > Save As command works even less well. In this case, it just opens up a plain white box -- but there are no drives or system folders of any kind displayed. No "Cancel" button either. I am, however, able to close the box by executing the "x" icon on top of the box. 

Interestingly, through testing, I realized that I am actually able to render a project -- but there are problems here, too. 

Selecting the "Render" button on the main GUI opens the "Rendering - Kdenlive" input box. However, I am unable to type anything in the "Output file" input area. And clicking on the "Select Output Destination" box to the right opens up another plain white box (that shows some of my system drives at left -- but not the individual folders, as I already experienced above). 

However, as an experiment, I tried just hitting "Render to File" to see if it would force a rendering. It did -- it created an "Untitled.mp4" file -- but in a new folder called "DoRcruments" off /home/user (file:///home/user/DoRcruments)!

I'm wondering if the problem is related to some missing library or other component that ensures proper network resource access between Kdenlive and Ubuntu? 

Many thanks. I look forward to your suggestions.