"There is not enough free space on the device."

SanDisk MP3 players Sansa® Clip | Sansa® Clip+
4
  1.  Please don’t dredge up 4 year old threads. Start a new one.
  2.  Read this SanDisk knowledgeBase article:

http://kb.sandisk.com/app/answers/detail/a_id/848/kw/not%20enough%20space%20for%20music