I think some examples in GLMExamplesBrowser In Pharo5.0 are broken. see fogbugz issue "16111 Collections being passed as a whole into blocks, instead of each individual object" The confusion about "display-block" and "format-block" is sorted out, so we could close the issue. But it seems the examples "Updateable browser" "Validating presentation" are broken (and maybe the Magritte example, but I don't know where it is).