Hi Anil,

The Wkhtmltopdf version you're using is not fully supported by Odoo. You should downgrade it to version 0.12.1.x. You can find more information about that here: https://github.com/odoo/odoo/issues/5177
You can install the correct version in the following way:

sudo wget http://download.gna.org/wkhtmltopdf/0.12/0.12.1/wkhtmltox-0.12.1_linux-trusty-amd64.deb
sudo dpkg -i wkhtmltox-0.12.1_linux-trusty-amd64.deb
sudo cp /usr/local/bin/wkhtmltopdf /usr/bin
sudo cp /usr/local/bin/wkhtmltoimage /usr/bin

P.S: this is for 64 bit. If you have a 32 bit version you should change the link to http://download.gna.org/wkhtmltopdf/0.12/0.12.1/wkhtmltox-0.12.1_linux-trusty-i386.deb

Yenthe