Ok, I've seen this once before. Can you try this: 1) Go into the Finder, right click on MixEmergency, then select "Show Package Contents". 2) Next, click "Contents", then "Mac OS" (you'll see and file with the name "MixEmergency" in this folder). 3) Open the Terminal Application (it's in your Applications/Utilities/ folder). 4) Drag and drop the "MixEmergency" file from the finder to the Terminal application. 5) Push the enter/return key in the Terminal application. This should open MixEmergency, and in theory, it should be working now. If not, can you try repairing disk permissions using the Disk Utility application.
