Halion 6 window disappears when dragging fxp file onto Slot Rack

Bump - can anyone advise how to stop the Helion window from disappearing when dragging an .fxp file onto it, or alternately, advise in which directory is best to put this .fxp to get Cubase (Pro 10.5) to read it on launch? It’s the INIL Choir (from 10cc’s “I’m Not In Love”) from Sampletech out of Sweden, they’ve not been very helpful despite sending me instructions & a video on how to drag it onto Halion, while I’m saying I CAN’T drag it onto Halion! So they’ve stopped responding & I have a plugin that I can’t use. Anyone? Thanks.