I'm not sure how long it has been a feature, but Last.fm allows you to change your username now through its Pro tier. However doing so seems to break scrobbling in programs like MusicBee.
I'm able to log in without an error message and it displays the red icon, but once I finish a song it switches to the grey exclamation point and nothing is scrobbled.
This must be due to a change on Last.fm's part because it's also broken another scrobbling program that I use.
In ErrorLog.dat it displays:
6/28/2020 5:50:32 PM - 10.0.18363.0 - 3.3.7477.36291D - System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at MusicBeePlugin.Plugin.ReceiveNotification(String sourceFileUrl, NotificationType type)
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object parameters, Object arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object parameters, CultureInfo culture)
6/28/2020 5:50:27 PM - FAIL (4) Invalid username/password:
Wire - The Other Window