P4TRUST

When Swarm is configured to connect to a Helix Versioning Engine (p4d) using an SSL connection, Swarm automatically executes the p4 trust command, which accepts the SSL fingerprint and creates the file SWARM_ROOT/data/p4trust containing a list of trusted servers and their fingerprints. If the certificate that p4d uses is changed for any reason, when p4d is restarted Swarm connections to p4d fail.

The solution is to delete SWARM_ROOT/data/p4trust. On the next request to Swarm, p4 trust is again automatically executed and Swarm can then connect to p4d.