So basically,  my friends have been having trouble installing 1.12 for Pocket Edition.

Their problem is, they go to the appstore and do not see the "update" button, to update to 1.12.

Their version is 1.11.4

I play on Windows 10 Edition and had no problem with updating. but since they can't update, we can't play multiplayer anymore!

Also, for the version of the Operating System, its generally all

Edit: They have tried re-installing Minecraft but it did not work