How do I deal with this Arduino IDE installation error? I am using Linux Fedora 20 (yes I am going to upgrade it, definitely, soon) and I have installed arduino-1.8.0, but I get this message ...  


  Your copy of the IDE is installed in a subfolder of your sketchbook.
  Please move the IDE to another folder


... when I click on the desktop icon, or run ./arduino. I have tried moving the tar.xz file to its own folder ArduinIDE again installed it but get the same message. Please,what should I do to get out of this? Please no answers like "just do what it says":in that case what do I move, and what criteria does the destination need to have?
Delete (or edit) your preferences.txt file - it most likely has your sketchbook folder set to your home directory.

You may find it in ~/.arduino15 for the "real" Arduino IDE, or in (I think) ~/.arduino for the arduino.org one.

Unless you have a specific reason for wanting to run 1.8.0, which is actually 1.0.6 re-numbered, you should be using the version from arduino.cc which is currently 1.6.13.