Your
dfm file does not match the
pas file.
When loading the form it streams the
dfm file and creates the components and places the references in the published fields if they exist (yes, you can have a component on your form but no field in your
pas file, if you don't need to
access it). But it does not work the other way around. If you placed your component field in the published part (which is by default if you dont specify the visibility) but never created it yourself.
Usually the
IDE also complains about this when saving your form (like "Field Form1.CheckBox1 does not have a corresponding component. Remove the declaration?")
Also: did you call inherited in your custom constructor?