Hi Dale, Thanks for your detailed suggestions. I follow instructions, here the report bellow. Installed newest Metacello, then Voyage with new style: Metacello new baseline: 'Metacello'; repository: 'github://dalehenrich/metacello-work:master/repository'; get. Metacello new baseline: 'Metacello'; repository: 'github://dalehenrich/metacello-work:master/repository'; onConflict: [:ex | ex allow]; load. "Fetch from voyage repo at github" Metacello new repository: 'github://pharo-nosql/voyage/mc'; baseline: 'Voyage'; load: 'mongo tests'. It still have the same error, do an upgrade of Seaside. Enclosed is the transcript for both Metacello and Voyage install. Seaside installed was 3.1.x. I don't know the x digit, it is not documented in an obvious way :( Hope it helps Thanks Hilaire -- Dr. Geo http://drgeo.eu