What might cause this "Unable to read Component" message?

Question

When pasting the TCM URI (tcm:191-371868) of a Component into the search box, we get the following message (the Core Service returns the same message):

"Specified argument was out of the range of valid values. Parameter name: itemId Unable to read Component"

The Component in question is present in the database, as I can see by the following:

SELECT [ID]
    ,[ITEM_TYPE]
    ,[ITEM_REFERENCE_ID]
    ,[PUBLICATION_ID]
    ,[VERSION]
    ,[TITLE]
    ,[SCHEMA_REFERENCE_ID]
    ,[APPROVAL_STATUS_ID]
    ,[CONTENT]
    ,[REVISION]

FROM [Tridion_cm].[dbo].[ITEMS]
where ITEM_REFERENCE_ID = 371868
and PUBLICATION_ID = 191
GO

and

SELECT [PUBLICATION_ID]
      ,[ITEM_REFERENCE_ID]
      ,[ITEM_TYPE]
      ,[ITEM_LOCK]
      ,[ITEM_LOCK_DATE]
      ,[LATEST_VERSION]
      ,[CREATION_DATE]
      ,[ITEM_LOCK_OWNER]
      ,[TRUSTEE_ID]
FROM [Tridion_cm].[dbo].[ITEM_REFERENCE_PUBLICATIONS]
where ITEM_REFERENCE_ID = 371868
and PUBLICATION_ID = 191
GO

We're on 2011 SP1 HR1

Answer 1

I had this recently with an upgraded database (2009 -> 2011 SP1 -> 2013). I don't know what caused it, and because I only had a very limited use to the database, I didn't really care figuring out what it was (other than reading the component then delete the database - long story).

Anyway, it turned out to be that one of my components had a reference to a keyword that was stored in the Component's CONTENT as xlink:href="tcm:0-0-0" and this was causing the failure to read the component. Because it fails at a very low level (TOM READ), the UI can't really cope with it.