I had, on my MacBook, the same issue described here: https://discussions.apple.com/thread/2695871 By attaching  my external displays (either VGA or HDMI), I was able to use only the screen where the menu bar was located and the “Arrangement” window in the preferences pane of OSX resulted blank. Apple’s thread suggests that by deleting the general preference [...]

I needed to use an Apple Time Capsule (actually backing up our home Macs) to share some files. The issue here is that Time Machine (OSX’s backup program) might use up all the space on the disk: there is no way to tell Time Machine to stop at a certain quota. Workarounds are known like [...]