Little Big Planet mash-up pack doesn't load on PS4 Bedrock

We just bought Minecraft PS4 on disc, when we tried to create a world using the Little Big Planet mash-up pack included with the purchase we encountered an error. These are the steps:

• go to Minecraft store
• go to player's owned packs
• select "LittleBigPlanetTM Mash-up"
• select "create this world!" - World template is initiated
• leave all options unchanged and select "Create"
• the message "Loading resource packs" appears
• after a while, the error message "there was a problem loading this world" appears