Friends list not loading issue fix
Pokemon Go may have started out as a more focused player in the game itself outside of the squad aspect, but Niantic has incorporated a lot of elements over the years, such as the ability to add friends and exchange gifts with each other.
In fact, Pokemon GO Fest was split into different times based on different things, one of which was specifically listed as Friendship Time. This hour brought out specific Pokémon and was intended for a number of people to send gifts around the world to unlock a reward. However, almost from the start of the first hour of friendship, friend lists stopped working for many people.
This was meant by going to your friends list and saying it failed to load the list, just didn't load it or froze while trying to open or sending a gift. This made it impossible for many to participate in this global challenge. Although the goal was met worldwide, it only gave people the chance to earn rare candies as gifts for a few minutes, when most couldn't even open gifts.
Unfortunately, there is no surefire way to fix this problem yet. You can try to force quit the game and restart to see if that does anything, but that's not a guarantee. Sometimes this will at least allow you to load your friends list, but will not allow you to open a gift, so you have to keep trying.
Given that there are extra friendship hours, I hope Niantic fixes this behind the scenes issue and we'll see a smoother one later today. For those affected, the next Friendship Hour on Saturday, July 25 will be at 16 p.m. ET. You can also consult the rest of the schedules of the habitat zones here.