I have just landed bug 1546915 <https://bugzilla.mozilla.org/show_bug.cgi?id=1546915>, in which I move and rename the following functions: * browser.accounts.createSubfolder is now browser.folders.create * browser.accounts.renameFolder is now browser.folders.rename * browser.accounts.deleteFolder is now browser.folders.delete As these functions only landed a short time ago in Daily, there is no deprecation warning. If your extension uses them, it will stop working at the next update. GL