Error in user queries, display_name mapping or query usage

[roborourke]

{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [display_name] in order to load field data by uninverting the inverted index. Note that this can use significant memory."}],"type":"search_phase_execution_exception","reason":"all shards failed","phase":"can_match","grouped":true,"failed_shards":[{"shard":0,"index":"ep-examplecom-user","node":"f6_ujmSdT0uPfOiZ0iSOeA","reason":{"type":"illegal_argument_exception","reason":"Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [display_name] in order to load field data by uninverting the inverted index. Note that this can use significant memory."}}],"caused_by":{"type":"illegal_argument_exception","reason":"Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [display_name] in order to load field data by uninverting the inverted index. Note that this can use significant memory.","caused_by":{"type":"illegal_argument_exception","reason":"Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [display_name] in order to load field data by uninverting the inverted index. Note that this can use significant memory."}}},"status":400}