Your fillers need to use Adobe Acrobat or the free Adobe Reader (Desktop or Mobile) to fill out the form and submit. Third party PDF viewer (like Chrome and Preview on the mac) do not support PDF forms very well
For more information see : http://forums.adobe.com/docs/DOC-2653
Do you know what unsupported characters were used?
I can't see any characters that I would think were unsupported and I still receive 4 errors that say that there are unsupported characters. Is there something that shows me where the errors are in the form?
I had the same problem with unsupported characters. Finally I found out that the unsupported characters were three ü (u Umlaut) the user "wrote" in a text field.
- How could this happen that most of the characters (many Umlaute, because I live in the german part of Switzerland) are supported and some are not?
- Is there a way to prevent the user to fill in these unsupported characters?