error message:

	Failed to open the extension pack [path details]

	Details: Extension pack name mismatch between the downloaded file and the
	XML inside it (xml='Oracle VM VirtualBox Extension Pack' file='VirtualBox')

solution: rename the extension pack using underscores (spaces in the error
message correspond to underscores in real life), e.g.:


Also try using the command line method of installing extension packs:

	VBoxManage help extpack