Hi Avisha,
Do you have other applications installed on this server - or else have you added customizations to your AtoM instance? The paths in this error message do not appear to be coming from AtoM. It is also not showing the same error message as you first reported (an Elastica exception).
I would recommend that you check earlier error log messages and see if you can find the relevant one.
Since the error message also implies that this relates to Elasticsearch, you can try using the search:status task to check on your search index, and make sure it is running as expected. You can run the following task from AtoM's root installation directory - if you've followed our installation instructions, this is typically /usr/share/nginx/atom. Run:
Please feel free to share the output of this command.
Additionally, we can check on cluster health with:
Again, please share anything you find there.