DOCSP-42724-invalid-document-filter-behavior (#464)

* DOCSP-42724-invalid-document-filter-behavior

* style guide

Author: amalhotra-mdb

source/reference/beta-program/document-filtering.txt

@@ -59,6 +59,13 @@ Limitations
 
 .. include:: /includes/document-filtering-limitations.rst
 
+.. note:: Invalid Document Filter Handling
+
+   If you provide an invalid document filter in the start request, ``mongosync``
+   does not crash. Instead, the start request fails. You can re-issue the
+   start request with a valid document filter without needing to restart 
+   ``mongosync``.
+
 Examples 
 --------