A friend of mine is also having this issue, at first, their packs were not working properly. Specifically Full of Life and RealCW, the llamas and horses were flashing white. Then when they tried to update the packs in the marketplace they would load to a certain point and crash the game to the main switch screen. They tried to uninstall and reinstall the packs, and they will not download fully. Now they cannot even open the marketplace.
A friend of mine is also having this issue, at first, their packs were not working properly. Specifically Full of Life and RealCW, the llamas and horses were flashing white. Then when they tried to update the packs in the marketplace they would load to a certain point and crash the game to the main switch screen. They tried to uninstall and reinstall the packs, and they will not download fully. Now they cannot even open the marketplace.