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Other than that, check the output of the Kerberos test page in Kantega SSO carefully. Is it highlighting any other problems? In particular: Any warnings about ticket KVNO and keytab KVNO mismatch?
If you encounter this exception:
SPNego Exception: GSSException: Failure unspecified at GSS-API level (Mechanism level: Permission denied)
It might be related to a setting -Dsun.security.jgss.native=true, please check if user running the Atlassian hos product host product (Jira, Confluence, Bitbucket, Bamboo) have access to the relevant GSS library or remove the setting if it’s not necessary.
Relevant libraries might include:
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