Mozilla has decided to pull On-screen Keyboard support for Windows 8 and Windows 8.1 from upcoming Firefox 44 (currently in beta) because of a bug that was causing OSK to pop up when a Bluetooth keyboard is connected to Windows 8.1 device (this should’ve been happened).However, the feature will continue to work in Windows 10.
Browser company also feels the On-Screen keyboard support hasn’t polished enough to ship in Win 8.1, but the feature has been already shipped and enabled in Firefox 43.
FYI, current Stable Firefox shows on-screen keyboard whenever an input is detected on Windows 8 or later, but Firefox doesn’t show OSK in desktop mode on Windows 10 but it does show in tablet mode when needed.
So Windows 8 and 8.1 users will find OSK missing in the next release, but they can enable on-screen keyboard manually in Firefox by toggling ui.osk.enabled” preference value to true.
Firefox 44 release notes will include this sort of wording for this change:’On-screen keyboard support was temporarily turned off for Windows 8 and Windows 8.1.’