I installed odoo 9 under ubuntu server 15.10 with wkhtmltopdf 0.12.2.4.
Everytime I print sales order, it raises error:
Odoo Warning - Warning
Wkhtmltopdf failed (error code: -6). Message: The switch --header-spacing, is not support using unpatched qt, and will be ignored.The switch --header-html, is not support using unpatched qt, and will be ignored.The switch --footer-html, is not support using unpatched qt, and will be ignored.QXcbConnection: Could not connect to display.
I've tried to solved this bug but still failed, help me please