Running from terminal produces this when I click "Open":

QPixmap::scaleWidth: Pixmap is a null pixmap
QPixmap::scaleWidth: Pixmap is a null pixmap
QPixmap::scaleWidth: Pixmap is a null pixmap
QPixmap::scaleWidth: Pixmap is a null pixmap
QPixmap::scaleWidth: Pixmap is a null pixmap
QPixmap::scaleWidth: Pixmap is a null pixmap
QPixmap::scaleWidth: Pixmap is a null pixmap
Removing cache at "/home/jesse/.cache/kdenlive-thumbs.kcache"
 // / processing file open
 // / processing file open: validate
Opening a document with version  0.93  /  0.93
 // / processing file validate ok
***********
FOUND GUIDES:  0 
**********
"Creating audio thumbnails (1/1)"

Hi there, Jesse. 

I cannot reproduce this bug, but I am running on Arch with a KDE desktop. 
Since you built from sources, I am assuming that you know enough to get you into trouble. 
:)

It might be that you are missing a dependency on your system. On Arch, the following are dependencies for kdenlive:

    hicolor-icon-theme
    knewstuff (knewstuff-git)
    knotifyconfig (knotifyconfig-git)
    kplotting (kplotting-git)
    mlt (mlt-git)
    extra-cmake-modules (extra-cmake-modules-git) (make)
    git (git-git) (make)
    kdoctools (kdoctools-git) (make)
    v4l-utils (make)
    cdrkit (cdrtools) (optional) – for creation of DVD ISO images
    dvdauthor (optional) – for creation of DVD
    dvgrab (optional) – for firewire capture
    ffmpeg (ffmpeg-full, ffmpeg-full-arm-git, ffmpeg-full-git, ffmpeg-full-nvenc, ffmpeg-git, ffmpeg-headless, ffmpeg-libfdk_aac) (optional) – for FFmpeg plugin
    libdv (optional) – for webcam capture (if FFmpeg is not installed)
    oxygen-icons (optional) – optional for xfce
    recordmydesktop (optional) – for screen capture
    xine-ui (optional) – for DVD preview

------------------------------------------
Of course, those are top-level dependencies that have their own dependencies...

Hey Evert,

Isn't trouble a programmer's chief title? :)

I'm new to the compiling source stuff, but yeah, I suspect you might be right. I'll cross-reference your Arch dependencies with Ubuntu's. Thanks for the helpful list. (I ran Antergos for a while, but it turned out, for using it for business purposes, I needed the benefit of a fixed release, stable set-up. Sucks, though. I admire the rolling release model.)

I'll comment after I've searched for a possible missing dependency.

@Evert, well I looked best I can, but I don't see any Ubuntu packages parallel to your list that I haven't already installed. 

After some research and tinkering, I've come up with this amalgamated guide that I've used to build and install Kdenlive from source on Ubuntu (it's a little sloppy, but it works for now. I plan to revise it once it's bug-proof and offer it as some kind of documentation). You sound a lot more savvy than me; maybe you can tell me if there's something in this process that's contributing to the issue?

Here it is_________________________________________________________________________________

INSTALLING THE LATEST KDENLIVE PACKAGE FROM SOURCE ON UBUNTU 15.10

_________________________________

BUILDING & INSTALLING MLT
_________________________________

Run these commands in a terminal or Konsole:

sudo apt-get install build-essential pkg-config libavformat-dev libavdevice-dev frei0r-plugins-dev frei0r-plugins libgtk2.0-dev libexif-dev libmovit-dev libsdl1.2-dev libsox-dev libxml2-dev ladspa-sdk libcairo2-dev libswscale-dev qtscript5-dev libqt5svg5-dev libqt5opengl5-dev libepoxy-dev libeigen3-dev libfftw3-dev git yasm libtool automake   autoconf libtool-bin libtheora-bin libtheora-dev intltool swig libmp3lame-dev libgavl-dev libsamplerate0-dev libjack-dev libsoup2.4-dev libvdpau-dev python-dev libkf5crash-dev libkf5filemetadata-dev v4l-utils

mkdir /home/jesse/Documents/kdenlive && mkdir /home/jesse/Documents/kdenlive/dev_files && cd /home/jesse/Documents/kdenlive/dev_files/

git clone https://github.com/mltframework/mlt.git

cd ./mlt/

INSTALL_PREFIX=/home/jesse/Documents/kdenlive

./configure --enable-gpl --enable-gpl3 --prefix=$INSTALL_PREFIX \ --qt-includedir=/usr/include/x86_64-linux-gnu/qt5 --qt-libdir=/usr/lib/x86_64-linux-gnu

make

make install

INSTALL_PREFIX=/home/jesse/Documents/kdenlive && export LD_LIBRARY_PATH=$INSTALL_PREFIX/lib && export XDG_DATA_DIRS=$INSTALL_PREFIX/share:$XDG_DATA_DIRS:/usr/share

_________________________________

BUILDING & INSTALLING KDENLIVE
_________________________________

Run these commands in a terminal or Konsole:

sudo apt-get install libkf5archive-dev libkf5bookmarks-dev libkf5coreaddons-dev libkf5config-dev libkf5configwidgets-dev libkf5dbusaddons-dev kio-dev libkf5widgetsaddons-dev libkf5plotting-dev libkf5notifyconfig-dev libkf5newstuff-dev libkf5xmlgui-dev libkf5notifications-dev libkf5guiaddons-dev libkf5textwidgets-dev libkf5iconthemes-dev kdoctools-dev libkf5crash-dev libkf5filemetadata-dev extra-cmake-modules libsm-dev libv4l-dev libav-tools cmake qtdeclarative5-dev kde-runtime kinit kio breeze dvdauthor dvgrab xine-ui

cd $INSTALL_PREFIX/dev_files/

git clone https://www.github.com/KDE/kdenlive

mkdir ./kdenlive/build && cd ./kdenlive/build/

export LD_LIBRARY_PATH=$INSTALL_PREFIX/lib && export XDG_DATA_DIRS=$INSTALL_PREFIX/share:$XDG_DATA_DIRS:/usr/share && export PKG_CONFIG_PATH=$INSTALL_PREFIX/lib/pkgconfig

cmake .. -DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX

make -j4 install

cd /home/jesse/Documents/kdenlive/bin/

DONE

I also had to make a bash script in /usr/bin/kdenlive with this in it:

#!/bin/bash
INSTALL_PREFIX=/home/jesse/Documents/kdenlive/
export LD_LIBRARY_PATH=$INSTALL_PREFIX/lib && export XDG_DATA_DIRS=$INSTALL_PREFIX/share:$XDG_DATA_DIRS:/usr/share
/home/jesse/Documents/kdenlive/bin/kdenlive

If I ran it striaight from ~/Documents/kdenlive/bin/kdenlive, then ALL of the icons would get jacked up (see the images I'm attaching below this comment).

Created attachment 97254 [details]
Icons when program is run from ~/Documents/kdenlive/bin/

Created attachment 97255 [details]
Icons when program is run from /usr/bin with the bash script I created.

UPDATE: It seems that changing the style to "Fusion" restores the icons and the folder navigation functions. But, changing it back to Breeze makes the icons go away, again, and the folder navigation grays out again.

UPDATE #2: Looks like the "Oxygen" and "Breeze" styles are the only ones that aren't showing the icons properly, nor allowing the folder navigation function.

Any thoughts?

Good work on finding an icon set that does work. 
I was having a feeling that you were missing the icon sets, and this confirms it. 

The main issue here is that you are using a program that is developed on a KDE desktop with a GNOME desktop. 
There are workarounds, but you have to know your stuff, and things will always subtly break over time as the software changes.
Kubuntu is the same as Ubuntu, but with a KDE desktop, and may be a solution for you. Unfortunately, KDE is not the main desktop for the Ubuntu distrobution, and KDE subtly breaks over time on Ubuntu... 

You mentioned that you like rolling release distro's, but need stability. 

I am quite impressed by Arch. Also, I maintain the kdenlive-git package in AUR on Arch, so if you have an issue with it, I'll be much more likely to duplicate the issue and fix it. (Mainly because my kdenlive will be broken as well. :P)
To get stability on a rolling release, I recommend the LTS kernel, and using the snapshot feature of Btrfs, and only updating when you won't be needing your machine for a while.

Having googled a bit, it appears that there is also a breeze-icon-theme in apt. Do you have it installed?
http://packages.ubuntu.com/vivid/kde/breeze-icon-theme

The same may be true for Oxygen.

Alright, I gave in. I might've chickened out on Antergos because an update happened that had my whole software management apps down, and I got spooked. I installed Antergos with KDE Plasma 5.5.4, and naturally it works flawlessly. This issue doesn't exist.

I'd still like to see if there's a way to have this running smoothly from source on non-KDE desktops (as much of the community still doesn't use KDE). The reputation of Kdenlive would excel that much more if it worked the same regardless of the desktop/distro, but I get it's not that simple.

Anyways, thanks Evert for the little nudge back towards Antergos/Arch. I solved the biggest issue with screen tearing (which was the final straw that had me pull away from it), so I'll give it another run. :)

Marking this bug as resolved > invalid.

Hmm... 

I wonder if this issue also exists on Arch with a GNOME desktop. I'd have to make a virtual machine for it to make sure that it's not contaminated with my KDE libraries. 

Unfortunately my day job will keep me plenty entertained for the next week or so, and I will not have time to dick around with this. 

Honestly I have not had any reports on the kdenlive-git package about incompatibilities with GNOME on Arch.