Unfortunately, System Restore Explorer was still in its beta stages when its developer stopped working on the project. The application is now discontinued, so it isn't actually designed to work on Windows 10 even though, according to some of its users, it does.
As far as the error that you get is concerned, the same question was posted on the tool's official support thread, but it was never answered. As far as I know, System Restore Explorer requires you to have System Restore enabled and at least one already saved restore point in order to work, so make sure both conditions are met before running it.
Additionally, you could try running System Restore Explorer as administrator and execute it in compatibility mode with Windows 7 or an older Windows version.
