Explanation
The cause of the issue is that the host does not have access to the credential. This can happen if the host does not have the correct permissions or if the credential is not properly configured in the Vault Conjur Synchronizer.
The Vault Conjur Synchronizer is a tool that enables the integration between CyberArk Vault and Conjur Secrets Manager Enterprise. The Synchronizer synchronizes secrets that are stored and managed in the CyberArk Vault with Conjur Enterprise, and allows them to be used via Conjur clients, APIs, and SDKs. The Synchronizer creates and updates Conjur policies and variables based on the Vault accounts and safes, and assigns permissions to Conjur hosts based on the Vault allowed machines.
To fix this issue, the host needs to have the permission to access the credential in Conjur. This can be done by adding the host to the allowed machines list of the Vault account that corresponds to the credential, and synchronizing the changes with Conjur. Alternatively, the host can be granted the permission to access the credential in Conjur by modifying the Conjur policy that corresponds to the Vault safe that contains the credential, and loading the policy to Conjur. However, this may cause conflicts or inconsistencies with the Synchronizer, and is not recommended.
For more information, see the CyberArk Vault Synchronizer docs1 and the Synchronizer Troubleshooting guide2.