Notes

I apologize for any confusion. It seems there might be an issue with the code. Here's a corrected version:

```csharp
[HttpGet("get-appointments/{username}")]
public ActionResult GetAppointments(string username)
{
if (UserEvents.ContainsKey(username))
{
List<string> joinedEvents = UserEvents[username];
List<object> joinedEventInfo = new List<object>();

foreach (string joinedEvent in joinedEvents)
{
// Extract event name from joinedEvent string
string eventName = joinedEvent.Split(',')[1].Trim().Split(':')[1].Trim(); // Fix the index

// Find the event in Events list
Event eventDetails = Events.FirstOrDefault(e => e.Name == eventName);

if (eventDetails != null)
{
// Construct joined event information
var eventInfo = new
{
Name = eventDetails.Name,
DateTime = eventDetails.DateTime,
Location = eventDetails.Location
};
joinedEventInfo.Add(eventInfo);
}
}

return Ok(joinedEventInfo);
}
else
{
return NotFound($"User '{username}' not found.");
}
}
```

I corrected the index used to extract the event name from the `joinedEvent` string. Please try this updated code, and it should address the issue. If you encounter any further errors, feel free to provide more details, and I'll be happy to assist.