Impossible to reactivate the SSO following Australia upgrade

[CamilleSerruys]

Hi,
Please we encounter a big issue with our SSO, on PRODUCTION instance, we try many times to activate it (we deactivate it yesterday in prevision of the Australia upgrade). The connection test failed and we have errors indicated in the logs :

Error
27/06/2026 11:25:21
SAML2ValidationError: SAML Assertion decryption failed SAML2
Error
27/06/2026 11:25:21
SAML2: Could not validate SAMLResponse: no thrown error com.glide.ui.ServletErrorListener
Error
27/06/2026 11:25:21
Could not validate SAMLResponse SAML2 
Error
27/06/2026 11:25:21
SAML2: SAML Login Response Validation : Validation failed: SAML2ValidationError: SAML2ValidationError: SAML Assertion decryption failed: no thrown error


We try to contact the servicenow support and find that they don't answer on non-business hours, do you confirm this feature depends on the contract the customer deal with ???

And also , do you have any leads to help us with this issue ???

Thanks a lot !

Regards,
Camille

[Tanushree Maiti]

Hi @CamilleSerruys 

KB1641182 SAML2ValidationError : SSO not working -User is logged out 

Resolution

To resolve this issue, I recommend reaching out to your IDP team to create a new certificate. Once obtained, add the new certificate to the instance and associate it with the current IDP record.

To create a new certificate after obtaining it from your IDP team, please follow this knowledge base article (KB):
KB:https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0691439

Note: As it is production, in parallel raise a hi-ticket  with your vendor as Before Monday business hour - you have to fix it.

[CamilleSerruys]

Thank you for your quick response @Tanushree Maiti !

I’m going to move forward with the messages you send me....