Google calendar is a great tool for syncing your Outlook calendar events and appointments to your iphone automagically, over the air. You can configure the setup for one way sync, one way sync from google cal to Outlook 2010 or vice versa, or a 2 way syc so events added directly into the iphone are written to your Outlook calendar almost instantly.
Google knowledge base does not seem to have a solution for this type of sync issue (that is not an actual error code). In my experience out in the field everyday this is often and most likely related to corrupt cache data.
Close outlook. In Windows the directory is located in users/username/appdata/local/google/googlecalendatsync/data-files. Open data files and delete eveything in there. Restart your PC. Restart Outlook and test.