With the new minecraft safety features in place, i cant run forge in the mcl

So basically I booted up the mcl and it said mcl updating. I waited, it loaded. When it loaded in and I had forge as my preferred installation for play, it said something about safety features and stuff. I clicked on forge and looked at my other installations and it disappeared. Every time I try to use the forge installation it doesn't show up when I press create. What can I do?