Have other people seen this issue?
In the last three developer betas, I have been unable to set up Bootcamp. The installer will partition the disk, then it will ask for permission to install a helper app while simultaneously failing in the background.
In the console logs, I see:
| default | 23:59:38.725123 -0600 | Boot Camp Assistant | writing to output file got error: File too large |
| default | 23:59:38.725226 -0600 | Boot Camp Assistant | error processing data: Invalid argument |
(also filed as rdar://43633669)