iOS has an issue where some packs will fail to import. If you experience this issue, then follow the instructions from Mojang below to import your pack

Workaround

  • Download the add-on
  • Open the Files app and navigate to the “Downloads” folder.
  • Press and hold on the .mcaddon file to bring up a menu, then select “copy.”
  • Open the Notes app and create a new note.
  • Tap in the note to bring up the edit menu, then select “paste.” The file link will be pasted into the note.
  • Tap on the file to bring up a screen showing an icon, the file size, number of files, and “Preview Content” button.
  • In the lower left corner of the screen, tap the the “share” icon.
  • Select Minecraft from the list of apps in the bottom row of the share options.
  • Once you see the “import successful” message in Minecraft, you can safely delete the add-on from Notes and Downloads, because Minecraft copies the files to the appropriate game folder when it imports them.