"Nonce has already been used"

[beamercola]

I get this every time. Am I doing something wrong?

Error Error Domain=AFNetworkingErrorDomain Code=-1011 "Expected status code in (200-299), got 400" UserInfo=0x6080000f4500 {NSLocalizedRecoverySuggestion={
  "status": 400,
  "message": "Nonce has already been used. Make sure your nonces are reasonablely random and large",
  "additional": "",
  "reference": ""
}, NSErrorFailingURLKey=https://api.appfigures.com/v2/reports/sales?group_by=dates&start_date=2014-10-26

[mattt]

Nonces are automatically generated UUIDs, which are guaranteed to be different each time. Unless the same generated request is being sent multiple times, this is likely an error from the API provider.