What does this warning mean?

[bohanlon_splunk]

Warning of the form "WARN CMRepJob - _rc=0 statusCode=500 err=No error" in splunkd.log.
Found on the cluster master of an index cluster.
Cluster master appears busy replicating buckets following a change to maxdataSize stanza's, so may be related to this.

[bohanlon_splunk · Accepted solution]

Apparently this message is meaningless by itself.
The error is probably a socket error.
Normally a line before that one reveals the true error.