In case of downgrade of the HMI SiteManager to any version lower than 7.1.00000, the HMI is not usable by the GateManager during the next 12 hours. It is possible to check if this issue would occur by checking what is the current version of an HMI before applying a downgrade.
It is a known issue due to an evolution of authentication method between SiteManager and GateManager since SiteManager 7.1.00000
It is a known issue due to an evolution of authentication method between SiteManager and GateManager since SiteManager 7.1.00000