No, they haven't fixed it. It happens in Parallels Desktop 12.1.3 also for both my Windows 8.1 Pro x64 guest and my Windows 10 Pro x64 guest. Ready to bail on Parallels after working with their support people on this without resolution... For me, the black screen happens when un-suspending a suspended guest in either windowed or coherence modes. or when going from coherence mode back to windowed mode. In the latter issue, the funny thing is, at first the full Windows desktop is drawn properly inside the window, but then a split second later a black screen appears. Number of monitors doesn't seem to be a factor as it happens when theres either 1, 2 or 3 monitors attached to your Mac.
I wish that Parallels would create a multi-window mode option whereby in Windows each monitor can be a Mac window with the capability of spanning the mouse pointer across each of them whether it be 2 or 3 monitor "windows".
Basically, I want to run 1 Mac monitor, and 2 windows monitors and still be able to move my mouse between the three of them without doing a "Ctrl-Option" click to get the mouse two switch between macOS and Windows OR a truly working version of Coherence which right now I am calling "Incoherence".