Wow, if it HAD worked but doesn't now, that can only be due to a Windows 10 update. Are you on RTM or Insider version? If on the former, your post here will or should generate one of the Insiders to report it for you.
My experience was that it worked, as I put 9.8.2 on the build 10240 of Win10 (the RTM version), but I stopped using it and had no updates.
If it doesn't work, the problem might be similar to Windows 7, which handles graphics differently and sometimes produces a blank screen when you hit the fullscreen Graph display. That same problem occurred in DOS Lotus 123, on Windows post-XP.
Now, there might be a fix coming. For a whole lot of people in business, still use SmartSuite. IBM won't be helpful here, all they told me to do was not even install Win7. But excepting that graph thingy, SmarSuite works fine in some versions of Win7, 8, and in 10 like you said, it also worked.
So the quickest solution would be to assume a Windows Update is the problem. Can you roll back each update, and test when the graph starts working again?
Edited by brainout, 06 November 2015 - 11:21 PM.