New 16" won't install betas

Not unusal for new released HW. Apple will need to release an updated beta to include 16" support. I suspect a new beta will be released sometime this coming week with 16" support.

Thank you so much. That's what I thought but wanted someone to confirm it.

I hope your correct. I used the migration tool and put my old laptop in target disk mode.

My old laptop was already on 10.15.2, it warned me that my new laptop should also be on 10.15.2 and I tried that, it failed, so I ignored and ran the migration from 10.15.2 to my new 16 on 10.15.1.

Most things appear to work but I cant open my photo library and the error I get is its a newer library version. Hope this will get sorted out when 10.15.2 is available for the new 16 in .

If you reinstall your 16" using the Recovery Mode, Option-Command-R, option at boot you will install a different build of the current released version of Catinlina that was factory installed which is compatible with the 16" HW. See https://eclecticlight.co/2019/09/27/which-recovery-mode/ for additional info.The forked version includes support for the 16" differences in HW as well as the 10.15.1 supplemental update. See https://mrmacintosh.com/2019-16-macbook-pro-catalina-10-15-1-supplemental-update-19b2106/

Thanks so much for the reply. When I first tried to update the new 16 to 10.15.2 in target disk mode as it warned me my other machine was at a later release it failed and I had to go through a recovery mode on the 16 to get back in. I then put my old Mac in target disk mode again and re-ran the migration assistant. Reading the links you suggested I was first a bit concerned that I'd have to wipe and redo, though thats not such a big deal, just takes time.

However, looking at the great link you provied, I saw the following

"This means that as soon as you receive the new 16″ MacBook Pro, the 10.15.1 Supplemental Update (19B2106) will show as available."

I looked at about this mac on my 16 and I'm already on 10.15.1 19b2106 so I guess from that perspective I'm OK :-) and running the corrct forked build...

I guess I'll need to wait for 10.15.2 to be pushed to the 16 inch so I can get my photos back. Moral of the story, dont use the latest beta as target disk mode surce to load a new generation machine...

Who knows whether the photo database on the 16 that came from my old machine running 10.15.2 will work when I finially get to update the 16 to a higher version... Time will tell. For now when I open photos I see the following "The library “Photos Library.photoslibrary” is from a newer version of Photos. Please upgrade Photos to open this library."