The form I have been working on has increased to a massive size, 200+ fields with multiple rules on each field. Well, eventually my form has decided not to publish anymore, with the message "This form can only be opened in InfoPath filler". Due to this I saved and closed it, hoping it would publish after I restarted InfoPath. This turned out to be the biggest mistake of my life, since opening the form again caused half of the fields and sections to be deleted, and several other sections rearranged in a jumbled mess on the bottom. What the heck is InfoPath doing to my form?