Stream server for one host is not working but is working for another host -- this is urgent!!

[SplunkNewb]

I have looked at the configs files and they are configured the same however. im seeing the error below in the logs :

 ERROR [140550481172224] (CaptureServer.cpp:2295) stream.CaptureServer - /en-us/custom/splunk_app_stream/indexers?streamForwarderId=*********.tracfone.com status=504

[SplunkNewb]

I'm currently running splunk 6.6.2