I meet exactly the same problem.
I tried to update from 9.0.0 to 9.0.1 both downloading using the menu and copy the file to .update.
I see that the file is unpacked but it ends with the message as above,
Fortunately it reboots back in 9.0.0
I meet exactly the same problem.
I tried to update from 9.0.0 to 9.0.1 both downloading using the menu and copy the file to .update.
I see that the file is unpacked but it ends with the message as above,
Fortunately it reboots back in 9.0.0