Kentico v10: Error when running New Site Wizard

I am trying to create a new site in Kentico v10 using the New Site Wizard. I am NOT specifically importing data from an existing site (although I am aware Kentico will import a set of base data)...

I am guessing that something is corrupt in my database, but I don't know where to start. I cannot import a site either so I am pretty much stuck right now. Any help appreciated!

Step 1 of 6 - Choose default website

Creating a new site using a wizard

Step 2 of 6 - Enter new site settings

I enter only "Site display name" and "Domain name". Other fields use default values.

Step 3 of 6 - Object selection

I do nothing here, but click "Next" (so accepting all defaults)

Step 4 of 6 - Importing objects !! BAM !!

Error during import process ERROR:@@Error during import process Message: Value cannot be null. Parameter name: settings

Exception type: System.ArgumentNullException Stack trace: at CMS.DocumentEngine.TreeProvider.CreateSiteRoot(SiteRootCreationSettings settings)