While testing 0.19.0.rc1 I stumbled upon missing translations for some buttons. After finding one button was missing a translation I kept digging and found some more ...
Close button: This window opens when the user clicks "Create new receiving address" or clicks on an existing address and clicks "Show" under the "Receive" tab.
Yes/Cancel buttons: When clicking "Close wallet" from dropdown menu AND "Open URI" from "File" dropdown menu
OK/Cancel buttons: "Encrypt Wallet" from "Settings" drop down menu
OK button: all three "Help" dropdown menu items
Cancel button: "Create Wallet..." from "File" drop down menu
Some screenshots below:

