I had the same issue when I unchecked "Open documents as new tabs..." and didn't relate the Mysterious Disappearing % window to that til I read this comment. (Thanks!) Having being schooled under Apple's UI Group when I worked there, I learned "Thou Shalt Not Disappear Things on the User." I often need to fine tune documents to odd percentage settings. Please restore that option when I open docs in multiple windows!
I had the same issue when I unchecked "Open documents as new tabs..." and didn't relate the Mysterious Disappearing % window to that til I read this comment. (Thanks!) Having being schooled under Apple's UI Group when I worked there, I learned "Thou Shalt Not Disappear Things on the User." I often need to fine tune documents to odd percentage settings. Please restore that option when I open docs in multiple windows!