1) Avoid Using Preview (Mac users)
Mac users often find that PDF files default to opening in a program called Preview – this is fine for simple image files, but our PDF files are complex and Preview can’t handle them. If Adobe Reader is installed on your Mac, control+click the file you’re trying to open and select Open With—>Adobe Reader. If Adobe Reader isn’t an option, you need to download it by following the instructions below.
2) Update Adobe Reader
The number one problem people have when using our digital materials (Illuminations and WonderMaps, especially) is that they don’t have a recent version of Adobe Reader.
The easy way to check is to open up your version of Adobe Reader and under Help click Check for updates. This little feature can save you much pain and heartache. If your version is less than 10.0, you should get it updated. It’s free. Get it from Adobe.com. Install it, reboot the computer, and try again. Nine times out of ten this works. Don’t forget to set Adobe Reader as your default PDF reader for the future!
Please note: we released Illuminations updates for PC (12/2015) and Mac users (2/2016) to address compatibility issues with Adobe Reader DC. If you need a link to that update, please contact us.