MP3Tag is unable to read a directory

Is there a size or file number limit for a directory? The directory in question is about 9Gb and 1800 music files. I used to be able to open it OK but for the past few days I've been adding files and now when I select the directory I get the "reading directory" box but the green line stops at about 30% and MP3tag closes. Other directories seem to work fine. Any suggestions? I also uninstalled and reinstalled MP3tag, no joy,

What about checking the file system?
The "select directory" dialogue is a standard dialogue generated by the OS.
Also, the "select directory" dialogue does not show individual files but only objects of the type directories.
So really, I would check the file system first.
Then I would see if loading a folder always stops at the same file and then check that file for integrity.
If that is not really easy to find out, I would check all the files for integrity first with mp3val, mp3diags and/or foobar2000

Solved, I found an "empty" folder in the directory. When I moved it out everything works fine. When I try to delete the empty folder, Windows says it's not empty. Tried selecting show hidden files but still don't see anything so I just stashed it somewhere out of the way.

It would still probably be worthwhile to check the drive with this command from an elevated command shell:
chkdsk c: /v /f