Adobe Flash Install failed me for days, until I overrode the default DiscImageMounter, and selected 'Save File', as seen in the attachment.
There are two attachments here, one is about the above and the other a shot of the two types of downloads. The successful file is highlighted, and one that failed repeatedly is not highlighted.
I use OSX 10.8.5.
Please note that the .dmg file that succeeded is from Macromedia.com at 15.7MB , not Adobe, whose download came in at 1.1MB
Retrieving data ...