Up until about a week ago, when I was designing a form in Lifecycle, I could click from the design tab to the Preview PDF tab, see the PDF preview of my form, then click right back over to Design view. Now when I click on Preview PDF, first I get a quick message like an Internet Explorer error saying "Navigation to the webpage was canceled." Then the form will open in Adobe Pro, but it's not really a preview. It is actually opening Adobe Pro. How can I get back to where I can just click back and forth between design view and preview?