Secure Folder missing?

I can't seem to open Secure Folder anymore, it's missing from the launcher (I've tried both the default and Nova launchers), it shows up on the app list and on Galaxy Apps, but the Open button is greyed out. I had reset my phone about 3 weeks ago and it's been like this ever since, I just didn't mind it because I didn't need to use it up until today. I have no idea what happened or how to fix it, please help.