Hello,
You need to make test of the plugin version we sent you. What file sharing service works for you?
Try to download archive of the plugin by new link from the Private Content area.
Just open the Appearance > Widgets tab before activation Storefront theme, and do not close this tab. Once tests will be done and you activate XStore theme back, go to Appearance > Widgets in new tab and compare content of widgets areas in 2 tabs. Maybe all will be the same, in case some widgets changes their places you, you need to place as they were, thats all.
Regards