KV Store initialization failed. Please contact your system administrator
Unable to initialize modular input "microsoft_graph_security" defined in the app "TA-microsoft-graph-security-add-on-for-splunk": Unable to locate suitable script for introspection..
From the logs it is clear that the cert was expired and you need to generate a new server cert.
openssl x509 -noout -enddate -in /opt/splunk/etc/auth/server.pem
/opt/splunk/bin/splunk createssl server-cert 3072 -d /opt/splunk/etc/auth -n server -c <FQDN>
/opt/splunk/bin/splunk show kvstore-status
-- Hope this Helps
net.ssl.sslCipherConfig is deprecated. It will be removed in a future release.
2020-11-23T06:21:24.238Z F NETWORK [main] The provided SSL certificate is expired or not yet valid.
2020-11-23T06:21:24.238Z F - [main] Fatal Assertion 28652 at src/mongo/util/net/ssl_manager.cpp 1120
2020-11-23T06:21:24.238Z F - [main]
***aborting after fassert() failure
2020-11-23T13:44:48.109Z W CONTROL [main] net.ssl.sslCipherConfig is deprecated. It will be removed in a future release.
2020-11-23T13:44:48.122Z F NETWORK [main] The provided SSL certificate is expired or not yet valid.
2020-11-23T13:44:48.122Z F - [main] Fatal Assertion 28652 at src/mongo/util/net/ssl_manager.cpp 1120