I wrong....... the error is relative to my root class ...
For this class i implemented the class method propertyAt: aKey ifAbsent: aBlock This is in conflict with : the Behavior originalName method implement: ^ (( self isObsolete and:[ self name beginsWith: 'AnObsolete ............ where isObsolete TClass is: self propertyAt: #obsolete ifAbsent: false Thanks for considerations, Dario > Ciao, > > i work to port some code from Pharo 4.0 to Pharo 6.1-64. > > My root class into Pharo 4.0 define the properties > > instance variable and some relative method: > > a) propertyAt: aKey ifAbsent: aBlock > > ^ self properties at: aKey ifAbsent: > aBlock > > b) propertyAt: aKey ifAbsentPut: aBlock > > ^ self properties at: aKey ifAbsentPut: > aBlock > > c) propertyAt: aKey put: aValue > > ^ self properties at: aKey put: aValue > > d)...... > > Now when i port this code into the Pharo 6.1-64 when compile the code > > the Behavior originalName method implement: > > ^ (( self isObsolete and:[ self name beginsWith: > 'AnObsolete ............ > > > where isObsolete TClass is: > > self propertyAt: #obsolete ifAbsent: false > > > But my class implement a specific propertyAt: > ifAbsent: method > > and the system generates errors and don't compile the code. > > > Thank you for every consideration. > > Dario > > > >