Hello,
Could you please close the PP5 form and reopen it by double-clicking on its icon. Are there any error messages before you try to preview the document(if there are, could you please post the screen shots or error numbers and messages here).
Also, this error may occur if a resource previously added to the form is now missing because the form's zip file has been tampered with : could you please open the PP5 with Winzip and make sure all the resources(images, postscript attachments, the data file and the PPD) you may have added before are still there.
Thanks.
Pierre P