Perhaps construct could display information about filesize of the saved file on each save, in a non-intrusive popup (e.g. appears just below the layout and events tabs). Not a popup that must be clicked (as this would be annoying every save), but something like a floating notification that can be closed, so the user must acknowledge it at some point, but doesn't interrupt their work flow.
Also, if the save process finishes and reads the file and detects 0MB filesize, then display popup error, since a project should never be 0MB. Wouldn't work with project folders tho, as other files could be manually added in.
dazedangels , your corrupt backup files, what file size are they?
I remember back in Construct 2, my C: drive was where my project was, and I had a tiny SSD in, and at one point I saved, it was successful, but little did I know, my C: drive was at 0 free space, and my project actually did not save successfully, it was 0MB in size! Save failed due to disk space, but Construct didn't hint this. Is it down to Construct to help? Not exactly,but I wish it could have just checked that the save file is not 0MB.
I learned the hard way to backup stuff. Which reminds me, I should check my automated backups are actually working...