I had the same issue. Refreshing the page updated the percentage and allowed me to download.
got this error one time also ... <Error> <Code>AccessDenied</Code> <Message>Access Denied</Message> <RequestId>TS3QPT4RHQ39RQKP</RequestId> <HostId> gTreTkkTOCT3SDR6ONpyt5XLdG4LtnU5J0yVYahokrFIBe1+rEX/qaPuaXKtbASEi3qEh5PIeoI= </HostId> </Error>
Having the same problem !