org.apache.solr.common.SolrException: no field name specified in query and no default specified via 'df' param

[jrgriffiniii]

This issue appears to occur under certain circumstances for Blacklight applications querying SolrCloud:

2018-11-14 02:58:26.323 ERROR (searcherExecutor-23-thread-1-processing-n:lib-solr3.princeton.edu:8983_solr x:reserves_shard1_replica_n2 s:shard1 c:reserves r:core_node5) [c:reserves s:shard1 r:core_node5 x:reserves_shard1_replica_n2] o.a.s.h.RequestHandlerBase org.apache.solr.common.SolrException: no field name specified in query and no default specified via 'df' param
	at org.apache.solr.parser.SolrQueryParserBase.checkNullField(SolrQueryParserBase.java:878)
	at org.apache.solr.parser.SolrQueryParserBase.getFieldQuery(SolrQueryParserBase.java:932)
	at org.apache.solr.parser.QueryParser.MultiTerm(QueryParser.java:564)
	at org.apache.solr.parser.QueryParser.Query(QueryParser.java:198)
	at org.apache.solr.parser.QueryParser.TopLevelQuery(QueryParser.java:130)
	at org.apache.solr.parser.SolrQueryParserBase.parse(SolrQueryParserBase.java:212)
	at org.apache.solr.search.LuceneQParser.parse(LuceneQParser.java:48)

(https://app.datadoghq.com/logs?cols=%5B%22core_host%22%2C%22core_service%22%5D&context_event=AAAAAWcQJ9uLlGVmBAAAAABBV2NRSjl1N3NnTnZVZW1CZ1g5bA&event=&from_ts=1542164296773&index=main&live=false&messageDisplay=inline&query=host%3Alib-solr3+service%3Asolr+filename%3Asolr.log&stream_sort=desc&to_event=AAAAAWcQJ9uLlGVmDgAAAABBV2NRSjl1N3NnTnZVZW1CZ1g5dg&to_ts=1542164306827)