BR 800 as a controller?

I'm not familiar with the BR but you will need to set it up as a controller. If it doesn't have it's own controller preset in the drop down box you'll need to use ACT. I have a couple of controllers set up using a both methods and they work fine.

The control surface set up is in Preferences->MIDI->Control surface. Search the manual for "Control Surface" There'll you find how to attach it and also links to ACT set up info.

Ok when you say has it's own I guess you mean preset?

A couple of things to check.......

Is it sending to the correct port (your controller port) that is assuming you have more than one. For example my PCR-800 has two ports, therefore I have to have the correct input port selected within the Control Surface dialogue.

Is it an ACT based preset where you may have to MIDI learn the controls - Click on a cell in the controller properties dialogue and then move the control on your controller that you want to use for that cell.

Then once MIDI learn is sorted you may need to ACT learn - Click on the ACT learn button towards the top of the properties box and then click the controls within Sonar that you wish to assign, such as channel fader, pan pot etc and then move the controllers on your surface in the order you want to assign them, relative to the click order. Then click on the ACT button again and you should get a message something like "You clicked x controls & x parameters, do you wish to save these?". Obviously click ok if you're happy. Hope that all makes sense.

If it isn't ACT based it may be a driver issue although I wouldn't have thought you'd be able to assign it if that is the case. Having said that a non x64 surface wil show up in brackets in the Control Surface dialogue box and not work. I know that because I've tried it with bitman's BCF surface controller.