Your cache folders contain quick access, stored files that help you zone faster or load the appearance of an object quicker.  Occasionally, corruption or old data can prevent these from loading correctly.  This can be corrected by clearing out your cache folders.

To do so, select the Advanced Tools option in the lower left hand portion of your Launchpad after you have logged in.  Select Open Game Directory from the Advanced Settings List.  

Highlight and delete the folders for assetcache, cache and any logincache you have listed and re-patch.  To re-patch, simply close out the application and run it again.