Unfortunately, we discovered a few important changes that had to be made to the migration guide. These are UI related changes specifically impacting libraries. Here are some previews of the new additions:

The LazyBasicSnapperButton constructor has been changed to not perform any auto sizing unless passed a size of (-1, -1). All subclasses should modify their constructor's default size parameter to match the new default in order to retain auto sizing.

BriefcaseNotificationHandler has the following changes to its constructor:

Removed: public constructor() {}
Added: public constructor(Control owner) {}

BriefcaseNotificationDropdown had the following public methods extracted into a free function:

Removed: extend public TreeViewItem getItem(MyConfiguraBriefcasePost p);
Added: public TreeViewItem getBriefcaseItem(MyConfiugraBriefcasePost p, int maxWidth=500);

Again we apologize for any inconveinence