Lost final code and don't save

hi when I try to save the html window with ctrl + s it doesn’t save, it loses a part of the final code. if I try to save with file-save it gives the same error, what should I do?

I don’t know how to solve your problem.
But I throw in an idea which I find useful.
Install local-history package.
In $HOME/.atom/local-history/ you will see an archive
of every file opened in Atom editor. This history can be very useful and archived files can be sorted by a file manager into date order.