ns1:searchValue xxxx /ns1:searchValue
platformCore:code INVALID_SAVEDSEARCH /platformCore:code
platformCore:message A saved search with the internal ID 225 does not exist.
You might receive the error because the Role being used for web services does not have access to the saved search in the question. Either ask the owner of the saved search to make it public or give access to it since the saved search is attached to the item record as an sub list. You can also set the Search Preferences in the WS request to include only "Body Fields" so that it does not load up the sublist fields and a valid response is received.