Hi Katie
Sorry for the trouble with your OALD.
This sounds like a problem caused by an update to Adobe Flash Player.
Could you please try the following:
1. Download http://www.oup.com/zip/elt/Oald8_FlashPlayer10_Patch.zip and save to your Desktop, and double-click to extract the contents - it contains two files, flashplayer.xpt and Flash Player.plugin
2. In Finder, right-click on oald8.app and select "Show Package Contents"
3. navigate to the directory Contents/MacOs/plugins
4. move the two files from archive "Oald8_FlashPlayer10_Patch.zip" to this plugins directory
5. delete the oald8 user preference directory ~/Library/Preferences/oald8 . Please note that '~' represents your home directory, and that this step may need performing for each user who has used the dictionary
6. restart OALD 8
If that doesn't work, please get in touch with our support people: eltdict.help@oup.com
Best wishes,
Tim Teasdale,
ELT Dictionaries,
Oxford University Press