Hi, With the AST changes, we now create the RBMessageNode with a selector. Before it was an array of parts, which means that the Symbol was not created in the Parser. This means, we used to check in the Semantic Analysis when visiting the RBMessageNode if the selector already is in the Symboltable and raise a warning else. After discussing with Pablo, we decided to not implement this functionality on the level of the Parser (where the symbol is now created). - this is purely a âlintâ like warning. It has nothing to do with Syntax (nor with semantics). - it should be implemented on the tool level - it should not raise the annoying dialog, but instead put a red line under the symbol - The non existing selector is coloured red by the syntax highlighting already now (until you acceptâ¦) Thus: We will for now remove the warning, it will come back as part of the IDE later. There we will be able to do a *much* better job, too. (e.g. not check against existing symbols, but existing method selectors). Marcus