Whenever I open Lightroom, it says "your disk "Macintosh HD," which contains your Lightroom catalog, is critically low on space. Please remove files or empty the trash to make at least 20 MB available." I have only used .1/165GB so why is this happening? And it is stuck on the screen and every time I press ok the message pops up again so I cannot continue editing or exit or anything!!
Please disconnect any external (USB) device connected to the computer.
Change the Destination folder location to the internal hard drive e.g. Desktop in File > Auto import.
Let me know if this helps.