Run the command "unload-hotfix" on the SlickEdit command line. It will display the hot fix and allow you to unload it.
The new multiple instances code has a bug which can't be hot fixed. We will need to build these initial hot fixes into a new installer (25.0.0.9). This will take a day or so. Sorry for the hot fix loading problem. This hot fix needs to be pulled so the wonderful new multiple instances support isn't broken.