I had this issue also by another user last days.. There are two causes for this error raised by geocaching.com:
- You are a basic member and downloaded more than 3 caches.
- You are a premium member and downloaded more than 6000 caches.
I think it´s the last one.. The 6000 caches per day for premium users is shared for all API applications. So if you done a big data refresh in GSAK, iCaching or L4C you can come to this limitation.
I will test the member status and show a different error message in the future.