I've added some manual activities from some time ago today. I forgot to set the date with one, so it was saved as "today". After editing it and changing the date, it still appeared on top of the "All activities" list instead of further down. When deleting it, it vanishes at first, but is back there when reloading the page. However, now, when trying to open the activity, an error page "Sorry, we're having trouble with this page." appears.
How can I delete that activity once and for all?
