After Upgrade Search head clusters 7.2 to 8.1 gettin error 'Web interface doesnt seems be available"

[MadiAvalos]

Hello all,

i am facing a problem
we have an environment of:

11 index (cluster) / 1 as Cluster Master

3 search heads (cluster)

1 SHC Deployer

2 deployment servers

3 Heavy forwarders

1 Enterprise Security 

The indexes, the deployment servers, the ES, forwarders and SHC deployer we could upgrade them without problem. All now are in 8.2 version
But the 3 search heads that are in a cluster, we get the error 'Web interface doesnt seems be available", the daemon does start it, but it does not start the web.
We deactivate some applications that are not supported with python 3 but still the web does not start.

[isoutamo]

If this is still valid questions have you check splunk log files on filesystems what there are? Usually splunkd.log and maybe some other logs have some hints what issue leads to this situation.
r. Ismo