It is a frustrating problem that I have on some heavy projects or some VSTs like chamber strings from spitfire audio. I think it might be a driver issue because when I change it from ASIO to WMD, sound comes back. I don't like to work with WMD because compare to ASIO it is a bit slower and I prefer to stick with ASIO. I am just wondering is there any buddy here has the same issue? Is there any solution? 
Do you think I should sell my vs700 and buy an RME?

I did have some silent master bus issues (where the master bus showed moving meters but no sound) which appeared out of the nowhere in some projects. I could never figure out a definite reason that would cause that so I eventually blamed it on a poor driver ...
 
Meanwhile on MOTU. Not seen that again.

I feel your pain ! I have exactly the same problem. I thought it may be because I am running Windows 10 with the driver hack and was seriously considering going back to Windows 8, but I see you are running Windows 8.1 so I guess I'll have to stick with WDM.

Do you think is there any possibility to have an updated ASIO driver and somehow force Roland to use it. I think one part of the driver is just for identifying the unit to Computer the another part is the ASIO driver.
If we can find a way to force vs700 to use the updated ASIO driver it might work.
I am just guessing.