Based on the critical diagnostic you're receiving and what you've described, it sounds like its possible that Form 8332 isn't part of the return, but is being attached to the return as a PDF.

The Link to form field is to associate the PDF attachment with the form/activity it is supporting. If there is no Form 8332 present, then this diagnostic will generate.

We recommend you check that the form you are trying to link the PDF to is active and part of the return, or double-check that it is the correct activity that it should be linked to.

For more information on PDF attachment, see here.

Hope this helps!