Technical Tip: OneLogin SAML SSL VPN Fails After Upgrade to FortiOS 7.0.15 or 7.4.3

[ssanga]

Description	This article describes how to resolve an issue observed in FortiOS versions 7.0.15 or 7.4.3 where users are unable to connect to SSL VPN using OneLogin as the IdP after performing an upgrade.
Scope	FortiGate v7.0.15, v7.4.3.
Solution	After upgrading FortiGate to FortiOS v7.0.15 or v7.4.3, OneLogin SSL VPN users may be unable to connect to the VPN. The problem can be verified by examining the logs as outlined below. diagnose debug application samld -1 diagnose debug application sslvpnd -1 diagnose debug enable . . 2024-04-24 11:40:39 [15580:root:a]req: /remote/saml/login 2024-04-24 11:40:40 [15580:root:a]readPostLeave:151 invalid character (13) in payload (/remote/saml/login). This issue has been resolved in FortiOS versions 6.4.16, 7.0.16, 7.2.9, 7.4.5, 7.6.0. Logs required by FortiGate TAC for investigation: Debugs: diagnose debug application samld -1 diagnose debug application sslvpnd -1 diagnose debug timestamp enable diagnose debug enable <Reproduce the issue> diag debug disable TAC Report: execute tac report The configuration file of the FortiGate.