Sadly, there are no useful information in the DXF file. It's size is to small to contain any entities and a deeper look showed, that it is corrupted already in the TABLES section, before any entity information.
With missing ENDSEC and EOF information, it's no surprise, that the file does not open in any CAD app.
The log file seems not to be related with LibreCAD, thus also no valuable information.
Because LibreCAD don't touch the file while drawing it's weird.
All information is kept in memory and auto save and backup is written to different files.
Only when one triggers File -> Save LibreCAD would touch the DXF file.
So when it crashes on deleting a layer, it shouldn't corrupt the DXF file.
Maybe there are two unrelated issues.
I opened the file with the latest LibreCAD version and it did not hang or crash.
So probably you use an older version and I recommend to update to latest release 2.2.0.
And you should also check auto backup and auto save settings in Application preferences, when you haven't found any DXF files containing ~ or #.
Have you used the file manager search function? Maybe the backup files are somewhere hidden in users home folder.
investing less than half an hour into Search function can save hours or days of waiting for a solution