Equally puzzling - and this may be related to the issue - is that the patterns files don't show up in "C:\Program Files (x86)\LibreCAD\resources\patterns" even though I can open them from that location from LibreCAD
Opening a file from LibreCAD:
Patterns available when trying to apply a hatch:
View from Windows 10 file manager:
The only pattern you see in Windows File Manager is gravel4.dxf, which was written after I changed the write permissions on the folder to "Everyone" . By default, a user should not be able to write to the Program Files folder, which might explain why the first few files don't show up. But I don't know why they are available from LibreCad ???