Hi, I just installed SONAR PLATINUM. The programme is unable to detect my audio interface (Roland UA-25 Ex).
The latest driver has automatically installed (ua25ex_w10d_v100), however when I open SONAR/Edit/Preferences/Audio/Devices the input and output drivers menu is blank. The device is working fine in other applications (iTunes, Audacity, Guitar Pro). Has anybody encountered this, or do you have any suggestions? Thanks

I had that same problem with Roland drivers.  To fix it I did one (or a combination) of the following:
 
1.  Check the audio drivers in Sonar and make sure no other drivers are listed.  If any other drivers are listed
    I uninstalled them even if they aren't checked as the drivers to use.
2.  Reboot my computer.
3.  Uninstall the Roland drivers then reinstall them.  (Make sure you get the newest ones off their web-site).
 
I hope this gets you going.  Good luck!!

Did you check the connections from audio interface to computer?
Do you have firewire or USB or digital connection?

Make sure you have the correct driver type selected in preferences (ASIO / WDM / WASAPI).  Not sure which driver type you have, but if you have the wrong type selected then it won't see your device.

lapasoa
Did you check the connections from audio interface to computer?
Do you have firewire or USB or digital connection?

YES!!  Once I couldn't get any sound out of SONAR .  I was cussing Cakewalk and everybody involved.  It turns out my interface was unplugged.   I was soooooooo glad I hadn't started an angry here!!

Thankyou for all the helpful suggestions, folks. I got up and running. I think the problem was that the driver had become set to ASIO instead of WASAPI, and the Master bus was no longer assigned to anything.

You can try: Share devices with other programs in preferences.
not sure if it will help but if you are using other audio editors and they are still open
(even after close sometimes they stay running) it potentially could cause a problem.
 
I would also reboot sonar. Make abso positive there is not something wrong with your port.
this happened to me once and I blamed everyone, everything except myself
 

Gotta say Folks, now I'm up and running the sound quality on Platinum is sooo much clearer that my previous (SonarX2). Well done Cakewalk.
 

Mogus Rougus
Gotta say Folks, now I'm up and running the sound quality on Platinum is sooo much clearer that my previous (SonarX2). Well done Cakewalk.

If you think so, then you should consider investing in some serious audio cables.
http://www.noiseaddicts.com/2008/11/most-expensive-speaker-cable-world-audioquest-audiophile/