Hi Sven, Following on from a discussion I started in Discord development... Loading Zinc SSO in Pharo 8 currently causes problems because the Zinc packages in core Pharo 8 are out of sync with your repository (specifically https://github.com/pharo-project/pharo/commit/45b7de2b6c901112be04230faba485... caused problems for me). I was able to resolve the issue by modifying BaselineOfZincHTTPComponents>>baseline: to remove all references to the packages that are now part of core Pharo 8: BaselineOfZincHTTPComponents>>baseline: spec <baseline> spec for: #common do: [ spec baseline: 'NeoJSON' with: [ spec repository: 'github://svenvc/NeoJSON:v17/repository' ]. spec baseline: 'XMLParser' with: [ spec repository: 'github://feenkcom/XMLParser:v0.6.1/src' ]. spec baseline: 'XMLWriter' with: [ spec repository: 'github://feenkcom/XMLWriter:v0.6.0/src' ]. "spec project: 'XML Support' with: [ spec className: 'ConfigurationOfXMLSupport'; repository: 'http://www.squeaksource.com/MetacelloRepository' ]." spec package: 'Zinc-AWS'; package: 'Zinc-REST' with: [ spec requires: #('NeoJSON') ]; package: 'Zinc-WebSocket-Core'; package: 'Zinc-WebSocket-Tests' with: [ spec requires: 'Zinc-WebSocket-Core' ]; package: 'Zinc-SSO-OAuth1-Core' with: [ spec requires: #('NeoJSON') ]; package: 'Zinc-SSO-OAuth2-Core' with: [ spec requires: #('NeoJSON') ]; package: 'Zinc-SSO-OpenID-Core'; package: 'Zinc-SSO-Demo' with: [ spec requires: #('Zinc-SSO-OAuth1-Core' 'Zinc-SSO-OAuth2-Core' 'Zinc-SSO-OpenID-Core') ]; package: 'Zinc-SSO-OAuth1-Tests' with: [ spec requires: #('Zinc-SSO-OAuth1-Core') ]; package: 'Zinc-SSO-OpenID-Tests' with: [ spec requires: #('Zinc-SSO-OpenID-Core') ]; package: 'Zinc-WebDAV'; package: 'Zinc-WWS-Server'; package: 'Zinc-WWS-Client'. spec group: 'AWS' with: #('Zinc-AWS'); group: 'WebDAV' with: #('Zinc-WebDAV'); group: 'WebSocket' with: #('Zinc-WebSocket-Core' 'Zinc-WebSocket-Tests'); group: 'SSO-OAuth1' with: #('Zinc-SSO-OAuth1-Core' 'Zinc-SSO-OAuth1-Tests'); group: 'SSO-OAuth2' with: #('Zinc-SSO-OAuth2-Core'); group: 'SSO-OpenID' with: #('Zinc-SSO-OpenID-Core' 'Zinc-SSO-OpenID-Tests'); group: 'SSO-Demo' with: #('Zinc-SSO-OAuth1-Core' 'Zinc-SSO-OAuth2-Core' 'Zinc-SSO-OpenID-Core'); group: 'SSO' with: #('SSO-OAuth1' 'SSO-OAuth2' 'SSO-OpenID' 'SSO-Demo' 'Zinc-SSO-Demo'); group: 'WWS' with: #('Zinc-WWS-Server' 'Zinc-WWS-Client'); group: 'REST' with: #('Zinc-REST') ] This isn't directly usable by you since it replaces 'XML Support' with XMLParser and XMLWriter and it would break Pharo 7. But if we modified it to put in checks for Pharo 7 vs Pharo 8 it would somewhat future proof the code against changes made in core Pharo 8. What do you think? Thanks, Alistair