Try a couple of other unzip utilities, as I find none of them works on EVERY zipped file. Stuffit Expander works on 85% of those I download. Ultimate Zip handles about 90% of the remainder. Of the others, Winzip or ZipMagic can handle a few, and a couple out of every few dozen I can't open at all. If you still can't open it, contact Curious Labs Tech Support. The link is on the Contact page, accessible from the their Home Page.