Hello it might be you need to : from: A Guide to Running Planeshift on Mac OS X
3. Use the built-in updater to get the latest files: Double-click the file updater(.app) in your Planeshift 3D folder. Once it finishes launching, click "Update," sit back and relax (you're in for a pretty long wait).
If it doesn't work, you'll have to do the following:
First, open Terminal (/Applications/Utilities/Terminal(.app)). In the new Terminal window, type "cd " (note the space " " after "cd"). Then, in the Finder, locate your "Planeshift 3D" folder, drag it into the Terminal window, and drop it there (text should appear after "cd "). Click inside the Terminal window and then press return. Then type "./updater.app/Contents/MacOS/updater" and press return. The updater should run and you can then click the "Update" button at the bottom. Sit back and relax; you'll have a long wait.
Hope this fixes it.