I've been working on a file for a week. When I opened it this morning it's completely blank. What should I do? I've tried zoom all and there's nothing there. Also there aren't any layers anymore either. It looks, as far as I can tell, a new file with no evidence of my work.
Hard to say what happened, without detailed information.
Which LibreCAD version do you use? Which operating system? Can you attach this empty file?
You can look into your project folder, where you saved the file, maybe there is an autosave or backup file.
Use the file browser/explorer and look if there are files named #YOURFILE.dxf or YOURFILE.dxf~.
These files may be created automatically and could have an older version of your work saved.
You can rename them and then open with LibreCAD.
But it depends on your settings if these files are there at all.