When the cache file is not created yet, libcouchbase outputs message on the ERROR log level
This message does not tell what is going on next. In fact, the libcouchbase will just continue to next configuration provider, loads the config, which in turn creates the cache file.
Another not so obvious error message is
Here what libcouchbase means is that it found the configuration cache, but the current lcb_INSTANCE does not have a bucket name associated yet, and it cannot apply the configuration cache.