I downloaded the ME version and installed it over the existing 8.1 installattion. It worked. However, the Extendscript Toolkit does not show up anymore. When i want to edit a script it seems nothing happens, but I can see in Task Manager that ExtendScript Toolkit.exe is running.
Problem solved, starting with Ctrl+Alt+Shift restored settings and Extendscript was visible again.
Thank you for let us know how you solved this problem! :-)