LR CC 2015 import problem

[mdijb]

I have a folder with many subfolders on an internal drive on my MAC.  I wish to import new photos into this folder.  It is clearly visible in the Library window left panel.  However, it does not appear in the import window, in the right panel.  It does not appear so I cannot select it as a destination.  I tried to SYnchronize this large folder, but this did fix the problem.

What is happening?  How do I fix?

MDIJB

[mdijb]

Bizzare--the missing folders in the import window suddenly appeared---?

MDIJB

[mbaginy]

I've experienced the same.  Have come to understand, that LR is a bit slow at times.  I simply wait a few minutes and all my folders and subfolders appear.