Full text search error: Invalid locale ID was specified
The answer was to Load Licensed Third-Party Word Breakers (MSDN)

From that link:


  SQL Server 2008 R2 includes licensed third-party word breakers for the following languages:  
  
  
  Danish
  Polish
  Turkish
  
  
  These word breakers are available but are not installed by default, and must be manually registered and then added to the list of LCIDs that are supported for full-text indexing and querying. 
  
  These word breakers are not enabled by default because they are owned by third parties who have not yet provided the level of testing, security, and robustness that is required for them to be enabled by default.




The main steps involved are:


Obtain Instance Name for Each Instance of SQL Server
Obtain the FTData Path for Each Instance
Register a Word Breaker and the Related Linguistic Components


Add the COM ClassID(s) for the Word Breaker and Stemmer Interfaces
Add a Key to the &lt;InstanceRoot&gt;\MSSearch\Language Node
Add Configuration Values That Give the Location of Each Linguistic Component 

Update the List of Languages Supported by Full-Text Search


See the linked documentation for the full details.