- On any Flow page edit some comment(s) and/or the description board
- Go to 'View history' and click on undo for 'edited a comment' and 'edited the description' antires.
The diff page to which you redirected, is dimmed and in a state of being loaded. Although, it displays: "The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit. " - the page never becomes active.
The same never-finish-loading issue for action that cannot be undone.
A separate question: 'edited the description' action made by 'Flow talk page manager'(http://test.wikimedia.beta.wmflabs.org/w/index.php?title=Talk:ET20&action=history) also has 'undo'. Is it what can be undone?
Note: 'unhide', 'undelete', 'reopen' actions - can be successfully completed.