I would like to notice you that when I install CRM module on Odoo 10 under OS Ubuntu 14.04, All sales data like "sales order" "Purchase module" all data related to buys and selling has been removed.

Here's screenshots of all data before I install CRM module on Odoo 10.

Screenshot 1: http://i.imgur.com/rFw4zO0.png

Screenshot 2 (Sales data): http://i.imgur.com/qsGU7Pa.png

Screenshot 3 (Purchases data): http://i.imgur.com/D6eVPoV.png

Screenshot 4 (Module): http://i.imgur.com/kv8fFAU.png

And here's the after module installation, as you can see on screenshot below all data has been removed, and also Purchase module disappear. after I tried to install Sales module (I found this module was uninstalled auto after installing CRM module)

Screenshot 1: http://i.imgur.com/fkbezOG.png

Screenshot 2 (Sales data has been removed): http://i.imgur.com/fHHHmmX.png

Screenshot 3 (Sales module uninstalled): http://i.imgur.com/1IuXuBN.png

I tried to reinstall Sales modules, but I cannot find any data. I am sorry for this long post, But I tried to be descriptive as possible as I can to help you get this error, and you may help me resolving it.

PS : CRM installation took around two minutes. I tried backup odoo database on fresh server installation but the same problem.