If you use nested data rooms and folders in DRACOON (with numerous subrooms or subfolders) in conjunction with very long names for rooms/folders/files so that the path length exceeds 260 characters, the items below them on the DRACOON drive will not be displayed in File Explorer.
For compatibility reasons, Windows only supports paths with a maximum length of 260 characters by default—even in File Explorer. If a folder hierarchy in DRACOON including filenames, for example, exceeds this value, the items located below it are not displayed in File Explorer and cannot be opened.
Starting with Windows 10 version 1609, you can use a registry value (and, alternatively, the group policy Computer Configuration > Administrative Templates > System > Filesystem > Enable Win32 long paths) to remove the path restriction to 260 characters, which makes using very long paths up to 32767 characters possible.
How to enable support for long path names in Windows 10: