The following actions uses node12 which is deprecated and will be forced to run on node16: actions/checkout@v2. For more info: https://github.blog/changelog/2023-06-13-github-actions-all-actions-will-run-on-node16-instead-of-node12-by-default/

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Nullability of reference types in type of parameter 'sender' of 'void PopupNotifierForm.PopupNotifierForm_VisibleChanged(object sender, EventArgs e)' doesn't match the target delegate 'EventHandler' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'sender' of 'void PopupNotifierForm.PopupNotifierForm_MouseMove(object sender, MouseEventArgs e)' doesn't match the target delegate 'MouseEventHandler' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'sender' of 'void PopupNotifierForm.PopupNotifierForm_MouseUp(object sender, MouseEventArgs e)' doesn't match the target delegate 'MouseEventHandler' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'sender' of 'void PopupNotifierForm.PopupNotifierForm_Paint(object sender, PaintEventArgs e)' doesn't match the target delegate 'PaintEventHandler' (possibly because of nullability attributes).

Non-nullable event 'LinkClick' must contain a non-null value when exiting constructor. Consider declaring the event as nullable.

Non-nullable event 'CloseClick' must contain a non-null value when exiting constructor. Consider declaring the event as nullable.

Non-nullable event 'ContextMenuOpened' must contain a non-null value when exiting constructor. Consider declaring the event as nullable.