If you are saying you have one gig of free memory you are going to continue to run into problems. This will get worse overtime because you are already hitting 0 bytes.

The operating system needs space to write out its files.

I strongly suggest you move essential files like photos a video media off to an external drive to free up some memory. These type of files being normally the largest and easiest to move. ( Do not delete any system files unless you know exactly what they are and removing them will not break you system)

Try and give yourself at least 10-15% free space. And keep within that.

If you are saying you have 1GB of free memory then the problem is not what is grabbing that 1GB but the lack of memory in the first place.

This will get worse overtime because you are already hitting 0 bytes and operating system needs space to write out its files.

I strongly suggest you move essential files like photos a video media off to an external drive to free up some memory. These type of files being normally the largest and easiest to move. ( Do not delete any system files unless you know exactly what they are and removing them will not break you system)

Try and give yourself at least 10-15% free space as a minimum and keep at or above that.