I just updated my system to Windows 10 Anniversary & UAD v.9.0, and I had the same "unsigned driver" problem with my Apollo Quad silver.
I solved opening a command prompt as administrator, and disabling the driver signature enforcement with the string:
bcdedit.exe /set nointegritychecks on
Unlike the "F7" trick I've seen around, this one works permanently, unless the feature is restored with the same string:
bcdedit.exe /set nointegritychecks off
Just some remark:
in case of the string isn't accepted by the system, either be sure to enter the command prompt as Administrator, and, if the bios of your machine has the chance to disable the UEFI Secure-boot in it, disable it before to launch the command string. It is possible you must clear the secure boot keys before the bios let you to disable the secure-boot (i.e on ASUS motherboards, like mine).
Of course, your system this way WILL NOT PERFORM ANYMORE any control on the drivers you will install; so it must be done VERY carefully, and you must be very careful to what you install.
I've not checked yet, but it is possible that the procedure must be repeated after every significant Windows update, in case it will restore the default signature enforcement.
This way, I've now a perfectly working system, waiting for a definitive solution from UA.
I hope this can help someone.