I'm having issues with Adobe corruption.

PDF corruption from client using Mac Preview to edit the file instead of Adobe.

Here is the workaround.  Preview the PDF in Google Chrome and hit Print, then choose “Save as PDF” as the printer.
That is how to get a clean copy.
Let me know if you need an in person walkthrough.
“[SOLVED] Text hidden on PDF form fields until clicked on
8 July 2013 by Adrian Gordon
You’ve got a PDF with form fields enabled. People are completing the form, saving the information and sending it back – however when you open the document the form fields appear empty.
When you click on the form fields the text appears, when you click away the text is hidden again.
This mysterious issue has been reported for several years without a fix from Adobe, however there does appear to be a workaround if you have the Adobe Acrobat software.
The issue appears to stem from Apple Mac users completing the form using the ‘preview’ software – which allows Mac computers to open PDF documents without AdobeReader being installed. The preview software appears to be corrupting the PDF, saving the form information but not displaying it correctly.”