One of Windows Subsystem for Linux’s more annoying tricks is it’s hard to get at your Linux files from Windows. Oh, you can do it, but you take a real chance of ruining the files. To quote Microsoft, “DO NOT, under ANY circumstances, access, create, and/or modify files in your distro’s filesystem using Windows apps, tools, scripts, consoles, etc.”
In the forthcoming Windows 10 April 2019 Update, aka Windows 10 19H1, this Linux file problem will finally be fixed.