It is not possible to log into Infrastructure Manager main hub. The error was 'no security'.
All other hubs were working fine. Restarted the main hub robot, Infrastructure Manager is not working at all - no hubs are visible on the list.
The security.cfg file is empty.
These are the errors in hub.log:
Aug 26 06:11:15:163 [19208] 0 hub: HUB SEC: HMAC mismatch
Aug 26 06:11:15:163 [19208] 0 hub: HUB SEC: failed to open security.bak (errno=28)
Aug 26 06:11:15:163 [19208] 1 hub: HUB SEC: backup of security file security.bak
Aug 26 06:11:15:163 [19208] 0 hub: HUB SEC: NewFile failed to open security.cfg (errno=28)
Aug 26 06:11:15:163 [19208] 0 hub: HUB SEC: new security file
The security.cfg file was empty.
Release : Any
Component : Infrastructure Management
Found that the disk on the server was corrupted. When it got fixed, UIM started working.