[keycloak-user] What Specification says my brokered IdP key is invalid?

I'm seeing a lot of messages like the following in my log file: 2019-05-22 14:28:56,312 WARN [org.keycloak.storage.jpa.KeyUtils] (default task-xx) The given key is not a valid key per specification, future migration might fail: f:jlab-ldap:ryans (1) What specification are we talking about? OAuth? What does it say? (2) I assume the problem is when I created an LDAP user storage provider I created it on the command line with specific ID "jlab-ldap". Why is this bad? Must it be a totally random UUID? The log messages seems to occur whenever a user links an account from a brokered IdP to their account in the Keycloak realm. (The brokered IdP is also Keycloak)