Both actually. Selection will not change the color of the text and even if you try to copy and paste it, you just see dots and not characters.
I have the same problem when using Preview on macOS.
I even tried using Adobe’s Acrobat Reader DC on Windows without success.
Could you make a version of the InvisiClues that was a Word document with white text on a white background? That should allow us to select the text to hopefully see the hints as you intended.
What did you use to create the PDF file?
Thank you all for reporting! That is rather odd, I'm a bit baffled. I don't really know what could be the problem; I used a LibreOffice document with black writing on a black background, and then exported to PDF.
Could it be because of the font? I used the Caterina font; maybe if it's not installed on your computer, it won't display and/or copy?
I will investigate and release a new version of the InvisiClues soon, possibly tomorrow. Thanks for your patience!
Hugo,
Yes, the fallback method does work for me. However, I would be interested in what PDF reader you used that was successful in reading your InvisiClues PDF. I was unsuccessful in both macOS and Windows. I was sure it would work in Adobe Acrobat Reader for Windows.
I just played with white text on a white background in Pages and exported the file as a .docx (Word 2007 or later) file. It worked exactly as you intended the InvisiClues PDF to work.
That might be a nice third option for those of us who cannot get the PDF to work, but like the idea of selecting the text to reveal the hint. I thought that was a clever idea.