My FF400 has been working beautifully on my current machine and set up, but now has stopped being recognised. I'm not aware of updating my OS but may have. My vocalist's FF400 has also stopped working at roughly the same time (she's on Sierra still) but that may be a coincidence. I'm trying to re-install drivers but it's not working, and I've noticed the Fireface Settings app refuses to load also. It's a little stressful as we're in the middle of a project and re-kitting ourselves will be hella costly. Any help would be greatly appreciated.