Hi, regarding the problem Sven mentioned on http://lists.pharo.org/pipermail/pharo-users_lists.pharo.org/2017-February/0... here are my findings: When I use latest Pharo 6 (Image 60404) and run Metacello new smalltalkhubUser: 'Seaside' project: 'MetacelloConfigurations'; configuration: 'Seaside3'; version: #'release3.2'; load it loads the latest release 3.2 (which internally loads 3.2.1). The package is "ConfigurationOfSeaside3-JohanBrichau.323.mcz" This loads fine in Pharo 6 except that after installation the "Tools" -> "Seaside control panel" is not working anymore as "NewListModel" is not found anymore. So the control panel is broken. Dont know what the migration path is for UI's who used the removed "NewListModel" class. So yes - one can (by using the above script) use Seaside but currently has to start the server with a script until this is fixed. This is good to know - but does not solve the "loading from catalog" issue. ----------------------------------------------------------------------------------------------------------------------------------------- So (in a fresh image 60404) I loaded "Bootstrap" from catalog and I received the error Sven reported. But ConfigurationOfBootstrap itself is not the problem I guess. Because it is also only referencing the "release3.2" version of Seaside and also "ConfigurationOfSeaside3-JohanBrichau.323.mcz" is loaded. The Transcript shows the following error output: Loaded -> ConfigurationOfSeaside3-JohanBrichau.323 --- http://smalltalkhub.com/mc/Seaside/MetacelloConfigurations/main/ --- http://smalltalkhub.com/mc/Seaside/MetacelloConfigurations/main/Error: Name not found: Seaside-Pharo-Development Also when you try to open the ConfigurationOfSeaside3 using Versionner I receiver an error "Name not found: Seaside-Pharo-Development". So there must be something wrong with the Seaside config I thought - or (what would be worse) with the newer Metacello version included in Pharo 6. At least the config looks OK and in both situations "ConfigurationOfSeaside3-JohanBrichau.323" is used. Additionally I tried: - when I load the Bootstrap config in a fresh Pharo 5.0 image (50769) from Catalog all loads fine. - when I manipulate the Pharo 6 image to have a version 5 signature SystemVersion newVersion: 'Pharo5.0'. SystemVersion current inspect. and load from catalog afterwards it also does not work. So I guess a Pharo 5.x specific config rule could not be the cause. Now I checked how Catalog loads the configs. And in class CatalogProject you will notice that for the catalog we still use Gofer for loading installStableVersion Gofer it url: self repositoryUrl; configurationOf: self name; loadStable when I change it to Metacello API installStableVersion Metacello new repository: self repositoryUrl, '/',self name; configuration: self name; version: #'stable'; load what a surprise: anything loads fine. I still wonder and do not know about the difference why Gofer and Metacello loading in Pharo 6 makes a difference now. So we could fix it for the catalog ... still I have no glue about the Gofer/Metacello API difference ... https://pharo.fogbugz.com/f/cases/19736/Catalog-should-use-Metacello-API-ins... Thanks T.