I use web clipper 6.1.3 in safari 7.04 on a Macbook pro running Mavericks 10.9.3. I've re-installed the web clipper a couple times and sometimes that helps when there are problems. One thing I have found is that the web clipper can be finicky. For example, I only see a revolving wait circle if I have my bookmarks sidebar open. I mostly use the web clipper to clip articles on the Science Daily website. I've found that if the clipper won't open, refreshing the page usually clears up the problem. Over and over, and somewhat randomly, the clipper stops functioning. Refresh the web page, and the clipper works just fine. Until it stops on some other page and I refresh again. Once in a while that doesn't work, but quitting and reopening safari, even with your tabs open, seems to reset the clipper and I'm good to go again. The clipper is so useful, and so essential to my workflow, that I've come to regard the glitches as just part of using the current product. The new mac operating systems due in the fall promise to make everything more seamless in the future.