I'm constantly having Finder issues with my rMB running 10.11.1. The most frequent problem is with folders not showing everything they contain. If I do a Get Info on the folder, other items magically appear (though, usually, not all of them). The only fix is a reboot, but the fix is temporary. Another, more occasional, problem is the Finder crashing when I try to open a file by double-clicking an item. This mainly occurs when said item is in iCloud Drive. The fix is the same: reboot. Are these known issues?