Hi, sorry to disturb. I have an issue on Windows7 (site said that it is supported). When finish installation of Multiplicity 3.57 instead of opening the Activation GUI it pops-up Web Page of Stardock.
That will happen if the PC's Windows root certificates are really old.
No doubt this PC is, or has been for a very long time, internet isolated.
A Windows Update usually fixes that but you can DL them manually.
Stardock Product Lifecycle Manager