Error message needs to be more informative when index is created while couchbase server is stopped on a KV node

Repro:
2 node cluster -
n0: kv, n1ql, index
n1: kv

1. Load data into default
2. Stop couchbase server on n1 (the kv only node)
3. Now create a gsi index.
Error returned is: GSI CreateIndex() - cause: Error Connecting KV 127.0.0.1:8091 Err dcp.invalidBucket

While error is expected, the error message can be more informative and suggest possible actions user can take , like "Index cannot be created when KV node is down and not failed over" or something better.