Drag folder to filelist frequently gives "Scanning - press ESC to cancel" indefinitely - and ESC has no effect.
I'm seeing that - in 4009, 4008, & 4007.
4006 works correctly.
Win7 x64, BRU x86.
Note that the file list window is "empty" - except for said message.
Statusbar correctly shows the number of items in said dragged directory.
The "urlbar" does correctly show the path of the said dragged directory.
The "items" are there in the file list window, yet you cannot
see them.
You can F2 (rename) them, during which time they do appear, momentarily.

On my Win7, I have all "visual effects" (whatever MS calls that ... crap [can't think of name, ATM] disabled (so I basically look like XP [in case that matters]).
(I've not seen the actual crash that the OP is getting.
Though I've never dragged a directory like this before, either.)
> Is it caused by a specific folder ?
No.
> Do you have custom column defined in BRU, a JavaScript setup, or extracting exif or file properties?
No.