ns_memcached exception causing memcached to not enable traffic

[ns_server:info,2019-07-05T13:40:34.824+01:00,n_1@127.0.0.1:<0.14325.0>:ns_memcached:do_ensure_bucket:1139]Created bucket "default" with config string "max_size=268435456;dbname=/Users/benhuddleston/Documents/couchbase/source2/ns_server/data/n_1/data/default;backend=couchdb;couch_bucket=default;max_vbuckets=4;alog_path=/Users/benhuddleston/Documents/couchbase/source2/ns_server/data/n_1/data/default/access.log;data_traffic_enabled=false;max_num_workers=3;uuid=4c37125604ce2ad061baecac6bcd2ac9;conflict_resolution_type=seqno;bucket_type=persistent;item_eviction_policy=value_only;max_ttl=0;ht_locks=47;compression_mode=off;failpartialwarmup=false"

[ns_server:error,2019-07-05T13:40:35.275+01:00,n_1@127.0.0.1:<0.13910.0>:ns_memcached:worker_init:183]Unexpected exception in ns_memcached for bucket "default": {error,

                                                            lost_connection,

                                                            [{ns_memcached,

                                                              worker_loop,3,

                                                              [{file,

                                                                "src/ns_memcached.erl"},

                                                               {line,205}]},

                                                             {ns_memcached,

                                                              worker_init,2,

                                                              [{file,

                                                                "src/ns_memcached.erl"},

                                                               {line,179}]},

                                                             {proc_lib,

                                                              init_p_do_apply,

                                                              3,

                                                              [{file,

                                                                "proc_lib.erl"},

                                                               {line,247}]}]}