Hi, i downloaded yesterday the latest Pharo 7 and in a playground if you do: class := Object newAnonymousSubclass. (OK) class package. "a RPackage(_UnpackagedPackage)" (OK) class compile: 'test ^nil'. (OK) (class >> #test) package. "nil" (Surprising but no problem with any pharo version since yesterday) class removeSelector: #test. (Exception, see below) An exception is raised in IceSystemEventListener class because the method package is nil: handlePackagesChange: packages IceRepository registry do: [ :repository | | changed | changed := packages anySatisfy: [ :each | repository notifyPackageModified: each name ]. "(EACH IS NIL HERE)" changed ifTrue: [ Iceberg announcer announce: (IceRepositoryModified for: repository) ]] So to fix it, the package needs to be correctly set for each method compiled in an anonymous class, but should anonymous subclasses really raise events when adding/modifying/removing methods? Steven.