Find and delete the folder com.mojang.minecraftpe (make sure to first). Fixing Standard "422" Connection Errors
Try these solutions in order. Start with the simplest (Clearing Cache) and work your way up to the nuclear options (Factory Reset). Download Minecraft Error 422 Android Fix
If you intended to download the "Error 422" horror version and it isn't working on your Android, keep in mind: What is Error 422 in Minecraft