Steps to reproduce

1. At demo, go to Pages app
2. Create a Page named "mainPageA"
3. Edit the page and within the main area, create an HTML component (text=Original). 
4. Create a variant of that component (text=Variant)
5. On the HTML component (variant selector of the green bar), select the "Original" which activates the "Copy item" action
6. Copy the HTML component
7. Now back to Pages app, on the same level than "mainPageA", create "mainPageB"
8. Edit the page and within the main area, clic on "Paste item"
9. The component is copied and you can check that both, Original and the Variant show the proper text message (Original and Variant)
10. On the HTML component, at the variant selector (Green bar), select original
11. Clic on "Delete all components variants" 
12. Check it fails (exception attached)

Expected results

All variants are deleted

Actual results

An error is thrown

Workaround

Restarting the Magnolia instance fixes the problem

Development notes

It seems like the new page is not marked as "page with variations" (Map<String, Integer> pagesWithVariants class property inside PersonalizedPages)
at info.magnolia.personalization.variant.PersonalizedPages when the component is copy-pasted.
If you restart Magnolia, the index pagesWithVariants is updated and you can delete the variant.