The following limitations are known for drag and drop:

On Windows hosts, dragging and dropping content between UAC-elevated (User Account Control) programs and non-UAC-elevated programs is not allowed. If you start with Administrator privileges then drag and drop will not work with Windows Explorer, which runs with regular user privileges by default.

On Linux hosts and guests, programs can query for drag and drop data while the drag operation is still in progress. For example, on LXDE using the PCManFM file manager. This currently is not supported. As a workaround, a different file manager, such as Nautilus, can be used instead.