What updates are required to run macOS 15?

[nbolton]

Steps so far:

1. Create new VM
2. Select 'Download ... from list'
3. Choose macOS 15 Beta 3
4. Wait for download to complete
5. Click install
6. Saw something like 'Update required, download?'
7. Clicked download and got an error about the update server not being available
8. Now every time I click install it hangs forever at the 'A software update is required' screen

Any ideas?

[nbolton]

Ah, just found this hidden behind all other windows:

[insidegui]

See also: #359 (comment)