Calibre not seeing iPad Mini 2

I've searched and read multiple forums, and I'm still lost.

Details:

Mac OS: 10.9.5
Calibre: 2.4.0

Plugins activated:
1) iOS reader with Marvin selected
2) Marvin XD

Additional:
* Auto Sync in iTunes turned off
* No additional devices plugged into mac

What I'm doing:
1) Reset Calibre multiple times
2) Plug in the iPad mini
3) Open Marvin
4) Go to "Get Books" and hit Calibre.
5) Look at Calibre on Mac and nothing.

Note: I am getting occasionally the following error window:

OSError: [Errno 24] Too many open files: '/Users/JRG/Library/Preferences/calibre/gui.json

Details:
calibre, version 2.40.0
ERROR: Unhandled exception: <b>OSError</b>:[Errno 24] Too many open files: '/Users/JRG/Library/Preferences/calibre/gui.json'

Traceback (most recent call last):
File "site-packages/calibre/gui2/dialogs/plugin_updater.py", line 157, in dialog_closing
File "site-packages/calibre/utils/config.py", line 408, in __setitem__
File "site-packages/calibre/utils/config.py", line 352, in commit
File "site-packages/calibre/utils/lock.py", line 139, in __enter__
File "site-packages/calibre/utils/lock.py", line 118, in unix_open
OSError: [Errno 24] Too many open files: '/Users/JRG/Library/Preferences/calibre/gui.json'


Is this possible the error?

Thanks all!