The SAML version of SITHS eID authentication stopped working in 4.3
This patch solves the problem.

https://files.phenixid.se/s/JrbWEHzmfHtcwn4

Replace the files in the zip file to the ones with the same name in this folder :
...\PhenixID\Server\mods\com.phenixidentity~auth-http~4.3.0\com\phenixidentity\authentication\handler\saml\

Restart the service

This patch fixes an issue where PhenixID Authentication Services (PAS) acts as a SAML broker (IdP with a SAML SP as authenticator). The issue occurs if a user avoid authenticating on the IdP, restarts the flow by browsing to the application, authenticate on the IdP. That flow may end up in "Unable to proceed" error which is fixed by this patch.

https://files.phenixid.se/s/rA72CCwQesjcgSw/download

Read the included README for further information