I was looking at your logfile yesterday actually, there's no errors and it just looks like a completely fresh installation, so I figured if you did have ND already on this machine and diagrams already created the workspace must've been created somewhere else!

It's great that you found where they were - extremely bizarre about the path too. What version of Windows are you using? We'd been testing on an Enterprise version of Win10 which it turns out behaved wrongly leading to the problems with the 1.11.0 release..

I'll reply to your email with the logs with steps to sort out your install.