I can't create an expense category in the Employee Directory module. I either get a blank screen or I get the error: 

"Uncaught Error: Unknown field product_variant_count in domain [["is_product_variant","=",false],["product_variant_count","!=",1]]

http://localdevip:8169/web/js/web.assets_backend/44bbe32:3519"

I'm using odoo's stable version .deb on Ubuntu 14.04 LTS 64 Bit.