On ubuntu 16.04, install from the stable ppa:kdenlive/kdenlive-stable. This will give you Kdenlive 16.08.2 and melt 6.3.0.

Just use the frei0r emboss effect (created with a previous version or with the fix below). If you click on the timeline where that effect is, Kdenlive will crash.

The dump will show you that the frei0r emboss library cannot find symbols sin() and cos().

Ideally, the library provided should be fixed.

If you execute the following steps in a shell, this will fix the broken library.

# install frei0r as the one provided is broken

git clone https://github.com/dyne/frei0r
cd frei0r
./autogen.sh
./configure --prefix=/usr
make
sudo make install
cd ..
rm -rf frei0r

# create missing kdenlive file

{
  echo "<!DOCTYPE kpartgui>"
  echo "<effect  tag=\"frei0r.emboss\" id=\"frei0r.emboss\">"
  echo "  <name>Emboss</name>"
  echo "        <description>Emboss the image</description>"
  echo "        <author>RG</author>"
  echo "  <parameter type=\"constant\" name=\"0\" default=\"375\" min=\"0\" max=\"1000\" factor=\"1000\">"
  echo "    <name>amount of azimuth</name>"
  echo "  </parameter>"
  echo "  <parameter type=\"constant\" name=\"1\" default=\"333\" min=\"0\" max=\"1000\" factor=\"1000\">"
  echo "    <name>amount of elevation</name>"
  echo "  </parameter>"
  echo "  <parameter type=\"constant\" name=\"2\" default=\"250\" min=\"0\" max=\"1000\" factor=\"1000\">"
  echo "    <name>amount of width45</name>"
  echo "  </parameter>"
  echo "</effect>"
} > frei0r_emboss.xml

sudo mv -f frei0r_emboss.xml /usr/share/kdenlive