I did the following:
- Downloaded Squeak3.7a-5657.zip (from the mirror in Magdeburg)
- Updated code from the Squeak Public Updates (updated to 5707)
- Opened the Package Loader
- Installed SystemChangeNotification 0.6 from SqueakMap

I got the following message dialog:
Error occurred during install:
UndefinedObject>>+

When I pressed OK i got a second message:
Error occurred during install:
My subclass should have overridden #changeKind

After pressing OK I got the same message a second time.

- Bernhard