I have Configured Indexer cluster and My problem is when I restart my indexers below Image will appear ?

[Dhanaskv]

I have configured the Indexer cluster (Heavy Forwarder, 3 Indexers, Master Node and Search Head)
My problem is when I restart my Indexers below Image will appear.so can't access the Splunk web page
can please help me? 

[isoutamo]

What messages you found from logs? (/opt/splunk/var/log/splunk). Especially splunkd.log usually told what is the issue. If needed you could look also other logs on same place.