Doktor Avalanche
Here is latest drivers and system program update from Roland's site:
http://roland.com/support...wnloads&p=A-300PRO
 
I installed it without any issue ages ago.
Make sure you use the correct drivers for your OS.

EDIT: This worked...somehow!!!  I uninstalled the Win7-x64 drivers.  Restarted the computer.  Then, reinstalled the same drivers.  Erased and reprogrammed the keyboard's flash with the "updSMF Utility" as I have been trying.  This time upon power up of the keyboard, it worked!!! So somewhere along the lines, the drivers must have gotten corrupt and somehow been affecting the flash/programming of the keyboard.  This part is the mystery...

 
Unfortunately, this didn't seem to work.  The next step I must take is power up the keyboard with just a DC adapter and completely eliminate the USB connection.  If it powers up but displays the same information on the LCD, then the A500pro may be broken somehow/someway.

Just to be clear (may have been stated earlier), what is the exact error message?

Doktor Avalanche
Just to be clear (may have been stated earlier), what is the exact error message?

Dok,
There was no specific error message.  The computer did not show any problems whatsoever.  The issue was on the keyboard itself.  Every time it was powered up, no matter how many times I tried to program it with the v1.15 firmware, it just displayed the version information and to press the ENTER button.  All steps afterwards would be to reprogram the thing again...and again...and again...

Yup I was talking about the keyboard. 
Is it displaying 1.15 version not an earlier version?
So it works on USB but not PSU..?
You said it was working but now not working?
Perhaps you successfully flashed it, switch it on and off and it reverted back after a power cycle? Did you read the documentation on the Roland site for the upgrade there are very specific steps.
Having said all that I don't own a power supply with my A300 Pro

Is it displaying 1.15 version not an earlier version?  Yes, it was displaying v1.15.  If I erased but did not reprogram, then it would display v.5.535 at power-up.
So it works on USB but not PSU..?  I don't have a PSU either, and the PSU has a negative center, so I never went this route.  Yes, it works off USB power now.
You said it was working but now not working?  No, it's working now.
Perhaps you successfully flashed it, switch it on and off and it reverted back after a power cycle? Did you read the documentation on the Roland site for the upgrade there are very specific steps.  Oh yeah.  I read it and repeated the steps several times to no avail.  Only after I reinstalled the Windows 7 drivers did it work successfully.

I have just seen this... I now have the same issue with my A-800... did you guys manage to find a solution?

Remove, reboot and install latest drivers from the Roland site. Take care to select the right OS. Install the latest system program if you haven't already.

Hi Everyone:
I have had the exactly same problem: from nowhere my A800 started to display the same message already described.
I manage to solve it, using the information provided for you folks, and a bit of luck.
This is what worked for me:
 
First:
There is a new driver for win 10 available from roland:
May be the cause of all this trouble was in the old driver, after all.
I did install this new driver (it's supposed to install automatically when you connect and turn on the A800 to the usb port / doesn't matter if the keyboard is displaying the annoying message). Check the instructions from Roland.
 
Second:
I found out that the only way to get this message from the A800 is when the switch underneath the keyboard is down (the left one): apparently this is the way the keyboard ask for a update of the firmware.
For details, refer to the Roland document here:
under the item: A-PRO System Program Ver.1.15. There is a detailed description on updating the firmware of the unit (which is the issue here).
 
Third:
I did the updating process as explained, and when the display of the unit ask to turn off I did so. It's supposed to just put back the switch at the upper position and turn the unit on.
BUT this time, before doing so, I cleaned a lot the area, vacuum the switch unit to prevent any dust around, and I moved several times the switch back and forth, to make sure there was a steady contact, and the unit didn't "think" I was trying to upgrade again.
And VOILA, it worked.
The unit went to the normal display, and is working just fine, as always did.
 
My guess is that for some reason the switch got stucked in the down position electric contact, even when the button was up - hardware malfunction perhaps -.
 
I hope this could help some of you having the same problem.
:)
And thanks for the help of previos posts.
Note: I did perform a full reinstall of Sonar before all of this. May be helpful for some of you, who knows.
 
 
 

Thanks for replying back.  I forgot that I responded to this post.  My A500 threw the error code as well, hence my inquiry.  Though not the A800, the A500 shares the same circuitry.  I solved the problem as well, and if I remember correctly, it was through the update process and updating of Windows drivers.  Something became FUBAR in the firmware, caused by itself.  I did nothing to the A500 to cause the problem, as the keyboard sits on my desk 24/7, never moving an inch.  I solved the problem quite some time ago, and I forget the specifics.  I do recall, however, that the update process did not go smoothly.  It took several tries and keyboard restarts.  Almost thinking the A500 was bricked, I contemplated throwing it in the garbage.  It wasn't until I updated the Windows drivers did it work again.  Very weird yet unacceptable. I'm sure many A500/800's have been, and will be, scrapped due to this problem from those not as patient.

What jdevit wrote above worked for me, I have previously had this problem and therfore already had the UpdSMF program.
As the link above does not work and you need the UpdSMF program let me know and I will send to you.