Just a heads-up, I installed the beta on both my primary desktop iMAc and my laptop (2015 MBP) and the desktop went fine but the laptop something seriously corrupted in the install, and now almost all of my non-apple apps fail on launch. Damnit what a pain in the butt.
Trying to install the 10.12 public release in effort to salvage... nope doesn't look like it's going to be possible. Dang it Dang it Dang it!
There is a way to install even though it says you can't, but, you have to edit the systemversion.plist in /System/Library/Coreservices.
I was able to edit this file but most people likely can't because of SIP, if that is the case you have to switch off SIP, next make a copy of it on your desktop and open it with a plist editor, you need to set the systemversion back to 10.12.0 and you might also have to set the built number back to (I think) 16A323.
After this delete the original one and replace it with the edited one, you need to enter your Admin password.
Next try to install again, it will show your disk, and not greyed out as before.
Anyone else seeing the beta come up with the mountain lion logo?
View attachment 660160
I had that too on my 2012 Mini but not my 2012 Macbook.
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Normally I always download the needed update files within Appstore but won't do the actual update in Appstore.
I go to /Library/Updates and install any updates manually, the reason for this is you can do it much faster than the System does it.
It worked for as long as I can remember but it doesn't work anymore, well at least if there are more than 1 .pkg files in that one Folder.
It's really a shame how Apple manages updates now, first it will close all your Apps and starts to install, after a reboot it takes another while before you can use your Mac again, this was so much better before!