Invalid characters Get<MyResponse>(MyRequest)

[Whoever]

Somehow a special character 0x0C gets into the database.  The handler returns MyResponse just fine, so I can't catch it in the error handler and logger on the service side.  But on client side, it throw exception at 

response = Get<MyResponse>(MyRequest);

saying invalid character 0x0C.  Is there a way I can avoid this without going through a comprehensive search and replace?

Thanks.