With the enterprise edition the cache tools app has an additional tab advanced

Expected behavior

This new tab should look similar to other default tabs like the browser tab.

Actual behavior

The advanced tab is closable (small "X" on the right side) which makes little sense because it can't be reopened again.
If the focus is on the advanced tab and it is actually closed an error will appear and render the app unusable. A reopen will solve the issue.

See screenshots, and the stack trace in the comments.