Cbdocloader error status 503

we are using couchbase server 4.5 in Centos 6.
The server is running fine but when we try to upload JSON files using cbdocloader we recieved the next error:
“Recieved unexpected status 503” .

We have installed sync_gateway too.
We haven’t seen any relevant information in log files.

Thank you!!

Hi here,

I’ve the same problem, anyone to explain it ?