So SC4 on the App Store has been updated to a new version, which promises "bug fixes." I have no idea what the fixes in question are, but if are going to update (or if you have automatic updates turned on), BACK UP YOUR PLUGINS FIRST. Sorry for the all caps, but I am staring at an empty plugin folder. Thankfully I backed them all up yesterday so I think I should be fine, but this is going to be a really unpleasant surprise for some people.
Yes, this was a nasty surprise. The aspire team never communicated anything about the update on the apple website about how the application would be effected.However, performing the update substitutes a completely new program package and a new plug-in folder. Copy your last plug-in folder from your back up and replace the contents of the new plug in folder with the contents of the old folder and you are good to go.
To get to the plug in folder just right click on the application and game data folder, where the plug in folder reveals itself.