first of all, thank you for this awesome editor, great work.
On Linux (CentOs 7.5) I'm having a crash when I try to open a directory after pressing ctrl+o.
After some investigation I probably found the issue.
On CentOs the default file system type is Xfs and according to this guy the d_type of a readdir always returns 0 on Xfs. It looks like that behaviour still is accurate and 4ed cannot figure out if something is a directory, link or file.