Description
Multipart geometry is not supported in the reference data when building a locator.
Solution
Use the following steps to correct the reference data and build the locator successfully:
-  Check whether the reference data has multipart features.
-  Run the Calculate Geometry Attributes tool to add the number of parts to the reference data.  A feature with more than one part is considered a multipart feature. 
Note:
The tools add a new field named PART_COUNT to the input.
 
 -  Run the Calculate Geometry Attributes tool to add the number of parts to the reference data.  A feature with more than one part is considered a multipart feature. 
 - Use the Multipart To Singlepart tool to convert the features in the reference data to single-part features.
 - Create the locator using the new reference data.