I had a similar issue with samples not loading (despite fervent double clicks) ...
At first after install (including all new versions of "everything else VSL and e-licenser," as usual) there was no path at all in the Settings tab of Synchron Piano player ... I tried this as a plugin in the "rack" of Cubase and also within VEPro6 ... manually added the Synchron Pianos folder to the list in Directory Manager ... still nothing in the path within Synchron player ... restarted a couple of times and re-installed Synchron Pianos (not sample content, just player). Restarted a couple more times and magically samples would now load, deploying the plugin in the Cubase instrument rack.
And I do mean "magic" - what incredible sound - instant inspiration and I started composing/improvising. But I digress.
Now I can play to my heart's content on the preset I chose, but the GUI is frozen - no response to controls, cannot open tabs such as CPU, Settings or Presets ... and there is a mysterious little box with an "X" in it superimposed on the velocity indicator strip in the upper left of the player.
I can re-load my saved improvisation project in Cubase, or start a new project and load a preset ... but then GUI freeze.
Any suggestions?
Ah, back to the "samples not loading" and path question ... can't open up Settings to see if the path has been "populated."
My system: Windows 10, Cubase 9.5Pro Build 9.5.0, all VSL software latest versions as of 5/7/2018.
Apologies if I have overlooked something "obvious" on my end - for example, could it be the Cubase build? Haven't updated that because everything has been working fine and busy with projects, so why rock the boat ...