[Samba] Samba 4.2, Mac clients not listing contents of some shares

[Eric Shell]

I have a samba 4.2 server with 69 shares, most of which function without
issue.  It is integrated with Microsoft AD for authentication and we have a
samba 3.6 server that is more or less working perfectly.  However, there
are a few shares on the 4.2 server that Mac clients (running 10.9, 10.10,
or 10.11) cannot navigate either through Finder or from within a terminal.
These shares can be mounted but their contents are invisible.  The
directory structure within the problematic shares can be navigated even
though no contents are listed, but no files can be accessed or written.
Attempting to touch a file results in an "Input/output error".

I added the vfs_fruit options from the man page example but the behavior
persists.  I'm not sure how to proceed with my troubleshooting; can anyone
suggest what to look at next?  Thanks in advance for any assistance.

My samba.log file contains some repeating errors but I'm unsure how
relevant they are to this problem:

[2016/01/13 07:54:26.452132,  2]
../source3/smbd/server.c:443(remove_child_pid)
  Could not find child 6577 -- ignoring
[2016/01/13 07:54:36.101764,  2]
../source3/modules/vfs_fruit.c:768(ad_header_read_meta)
  error reading meta xattr: Operation not supported