The save failed due to out of memory or disk space
I have a MacBook Pro and ran into this error message after trying to save a document. After searching online, I went into my Disk Utility and found two internal disks: the Macintosh HD (which had plenty of space and the remaining space I thought I had my computer) and Apple SSD which was full. The error came up when saving to a flash drive which has plenty of space and I thought I had plenty of space on my computer too. Can anyone tell me what the cause of this problem is and how to fix it? I've already run diagnostics on both internal disks and came up with nothing. Thanks!
MacBook Pro 13", macOS 10.12