The application "Preview", which is used for viewing images as well as PDF files, has support for entering text into editable fields in PDF documents. This is convenient for entering data into forms, but users are experiencing problems when trying to save the PDF with the entered text.
Apple Discussions poster syra writes:
"I'm filling out some PDF forms but when I press save all of my input text disappears."
While Preview supports inputting text in these fields, the program does not support saving the file as the original document. This is supposedly to preserve the original, since saving it would get rid of the ability to make further edits in the same field. Additionally, when users choose "Save As..." to save the edits to a new document, the program will not preserve the inputted text and instead essentially duplicates the original to the new location, leaving users with the same problem with not being able to save the document.
It appears this may be a small bug with how Preview handles the "Save As..." feature, especially since this is the recommended route for saving documents; however, it's possible this restriction is intentional since it is present in both Preview as well as Adobe Reader. Despite this, however, there is a way to save PDF forms with all the fields filled out.
Print the form to PDF When users choose to print a document, the system will convert it as-is to postscript and from there send it to printers. Since OS X has PDF rendering and creation built-in, these functions are available in many places, including the print dialogue. To save a filled PDF form, users should choose the print option from the "File" menu, and in the resulting print dialogue box select "Save as PDF" from the "PDF" menu. This will keep the entered text as is desired, but it will remove the ability to further edit the form. As such, users will not be able to enter text and save it, and then go back and change the document again. Instead users would have to start from scratch.
Use an authoring program PDF authoring programs such as Adobe Acrobat Professional should be able to enter items into text fields and save the document for further editing, but basic reader programs, including Adobe Reader, to not support this feature.