Update command not working

[Mike Thomsen]

I posted this to http://localhost:8983/solr/default-collection/update and
it treated it like I was adding a whole document, not a partial update:

{
    "id": "0be0daa1-a6ee-46d0-ba05-717a9c6ae283",
    "tags": {
        "add": [ "news article" ]
    }
}

In the logs, I found this:

2016-02-26 14:07:50.831 ERROR (qtp2096057945-17) [c:default-collection
s:shard1_1 r:core_node21 x:default-collection] o.a.s.h.RequestHandlerBase
org.apache.solr.common.SolrException:
[doc=0be0daa1-a6ee-46d0-ba05-717a9c6ae283] missing required field: data_type
        at
org.apache.solr.update.DocumentBuilder.toDocument(DocumentBuilder.java:198)
        at
org.apache.solr.update.AddUpdateCommand.getLuceneDocument(AddUpdateCommand.java:83)
        at
org.apache.solr.update.DirectUpdateHandler2.doNormalUpdate(DirectUpdateHandler2.java:273)
        at
org.apache.solr.update.DirectUpdateHandler2.addDoc0(DirectUpdateHandler2.java:207)
        at
org.apache.solr.update.DirectUpdateHandler2.addDoc(DirectUpdateHandler2.java:169)
        at
org.apache.solr.update.processor.RunUpdateProcessor.processAdd(RunUpdateProcessorFactory.java:69)

Does  this make any sense?  I sent updates just fine a day or two ago like
that, now it is acting like the update request is a whole new document.

Thanks,

Mike