Windows
On Windows, when trying to drag and drop a file into Genymotion Desktop, you may see this mouse cursor: . This means that the source file does not have the same permissions as the destination application. This usually occurs if Genymotion Desktop is run as administrator.
Genymotion Desktop should not be run as administrator. Please see Can Genymotion Desktop run in a standard user account? to fix this.
Linux
If drag'n dropping files does not work, this usually means that Genymotion Desktop is running as root.
Genymotion Desktop has been designed to be installed locally and should not be run as root nor installed to a system folder. Please reinstall Genymotion Desktop as a normal user in your home folder (for example: $HOME/genymotion).