Migrating a course from Lectora X to v17 means skipping 3 full versions that included lots of major updates. If I remember correctly especially the transfer of a course from X to 11 was a lot of work.
Doesn’t the error check or publishing process display any errors? Although a Go to action that has lost its target will display “Next page” instead of nothing in the action properties, it should produce an error message.
Is the Go to action the only action on that button? Is it the last action?