Hi there, Every few days on my Late 2013 rMBP, I get a message telling me that my available HD space is very low. And when I check, it is. Usually about 500MB. Which it shouldn't be as I try to keep about 8-10GB of free space. Other than the photos from my phone I don't really download any large files. When I go back to check my HD space a few minutes later, the free space goes back up to 5GB or more. For example - I got this message a few minutes ago which prompted me to write this post, and it has now gone up to 2.9GB of free space without me deleting anything. In fact, every time I refresh the amount of free space on my hard drive it changes - sometimes as little as 5MB, sometimes 100s of MBs or more. What is causing this? In the past it has caused me to be unable to download app updates, which can be really frustrating.