"This version of MacOS 10.12.2 cannot be installed on this computer"

[RMJ114]

I installed yosemite to my rig and it won't let me download sierra. It says, "This version of MacOS 10.12.2 cannot be installed on this computer"

My rig should be supported.

MB: Asrock Z68 Extreme3 Gen3
RAM: 16GB
CPU: Intel i3-2120 3.3GHz
GPU: GTX 650 Ti 1GB
Monitor: 1080P

Not sure what is going on. It should install it. It doesn't give me El Capitan to choose that route first, in case it wan't me to go in order, but I am installing to a new SSD and just want Sierra.

I installed Yosemite 10.10.3 and was able to upgrade to 10.10.5. I used Unibeast and Multibeast to install Yosemite.

Is there any hope for me?

Edit:

I also setup (default) Multibeast for Mac pro 3.1. Would changing that to something else make it work?

 

[trs96]

Yes, change your SMBIOS to iMac 14,2 and it will work.

 

[RMJ114]

Yes, change your SMBIOS to iMac 14,2 and it will work.

Is there a way to change this in Unibeast? I can't seem to find the right settings for multibeast. I am reinstalling 10,10,3 right now. maybe using 14.2 will make it work. I used MacPro 6.1 and failed and unbootable even with unibeast boot.