Adobe Reader. Cannot edit a form.

[Yan24352616do15]

 Hi. I already filled the window for "PHIL 101" a while ago with "REG SP22" as you can see in the video. But now, I cannot change this text box at all. When i click on it, another text box appears with the same text over, which i can edit but it becomes invisible after I'm done (Please see the video).

Looks like some weird bug, what could be the reason? How to fix it?

I had the same problem with another text box but it kind of magically fixed itself after I covered the text with a white Rectangle, then added another text box on it in a hope i can write what i need this way (it didnt work as the rectangle became transparent over the original text, so i just removed it, and it seemed to me that the weird invisible text box got removed too). This trick however didnt work with the text box in the video.

[Yan24352616do15]

Sorry, it turns out i cannot post videos here... I can send it to you somehow if you need.

Thank you.

[Lukas Engqvist]

As you say you can't post a video. But let me ask if you have opened the document in another PDF reade (such as Apple Preview), why I ask is that in my experience Apple Preview and some other File managers (network storage servers) can reprocess PDF files without informing or asking the User for permission. Just opening a PDF form in Preview will corrupt it, which isn't so easy since Apple sets this as the default application to open PDF files. Once a Form has become corrupt there is no way to reverse the corruption. Using Acrobat forms does to some extent require preventing other applications than Acrobat to corrupt the file.