I apologize. The dot is not supposed to precede the filename. That was not a real example. You are not supposed to put the full filename with a cluster upgrade. Please see a real example below:
Software to install needs to be like you see it. The MM will prepend a prefix for whatever platform will be upgraded. If you have multiple platforms, it will simply add the platform to the beginning of the filename. For example, if it is an 7005 to be upgrade, it will put ArubaOS_70xx_ in front of 8.4.0.0_68230 and look for the filename "ArubaOS_70xx_8.4.0.0_68230" on your FTP server. If it is upgrading a 7200 series controller, it will just put "ArubaOS_72xx_" in front of 8.4.0.0_68230 and attempt to download the filename "ArubaOS_72xx_8.4.0.0_68230" from your FTP server.
I hope that makes sense. When it comes to doing a cluster upgrade, you simply put the version and it will prepend the platform specific prefix and look for that filename.