I'm using Confluence 5.3.1. In the top title bar, "Spaces" shows a duplicate space under Recent Spaces.

The space "Decoder" shows up twice. I was curious about where this data is stored?
I don't need any history at all actually right now. Maybe I could just purge or delete all history.
Or if there is some other way to fix this I would appreciate any details or ideas. Thank you.
Mark