I just updated the launcher and it removed all of my custom installations from the launch menu and when I tried to make them again, it did not work. All the Optifine versions that I downloaded and all the previous versions of Minecraft are still selectable on the "Create" option, but the versions that I create do not show up.
Go into your installations tab and make sure that the "Modded" checkbox under Versions is checked. I personally wish it was prechecked, but I guess it's not.
Just make sure it's checked and it'll appear.