Articulate Storyline 360 closes down

Hi,

I have two issues  with which I would love some help, please. 

1. Storyline seems to take a very long time saving files.
2. Much more important, really - Storyline keeps closing down in the middle of working on a project. Sometimes when I try to save, I get the attached message.(memory image)

Please see attachment (version image) for version that am using.

There is no issue with storage on my computer, as I have plenty of available RAM, having had a recent upgrade.

Many thanks.

Kathy