Microsoft has quietly updated the minimum system requirements for Office applications for mobile devices. This is an unhappy information for people using old Android smartphones or running old Android.
Specifically, some Office for Android applications will stop working on devices running KitKat and Lollipop from July 2019. According to Microsoft, Office for Android will continue to operate on devices running the old operating system until June but then they will not be supported anymore.
Latest statistics from Google show that there are still many users using old Android. Specifically, Android 5.0 and 5.1 with the generic code name Lollipop are being used by 3.0% and 11.5% respectively. Meanwhile, Android 4.4 KitKat has 6.9% of users. Older versions of Android have about 3.8% of users.
If you use iOS, you'll get better luck. Microsoft confirmed that all mobile Office applications will still work well on iPads and iPhones running iOS 11.0 or higher. Currently, according to Apple's latest report, 83% of iOS users are running iOS 12, 12% running iOS 11 and only 5% running iOS lower. Therefore, Microsoft's mobile Office applications are supporting 95% of iOS users.
If you want to continue using Office for mobile devices, upgrade your smartphone or make sure you're running Android higher than KitKat or Lollilop.