Watchers are not working after elasticsearch migration 7.16.1 to 8.5.1

[mkaymak (Merve Namıduru)]

After migrating Elasticsearch version 7.16.1 to 8.5.1
The watchers which basically find the error logs and send them to our messaging channel started to not working.
When I simulate my watcher the error message is:

 "error": {
        "root_cause": [
          {
            "type": "null_pointer_exception",
            "reason": "Cannot invoke \"org.elasticsearch.xpack.core.watcher.watch.Payload.data()\" because the return value of \"org.elasticsearch.xpack.core.watcher.input.Input$Result.payload()\" is null"
          }
        ],
        "type": "null_pointer_exception",
        "reason": "Cannot invoke \"org.elasticsearch.xpack.core.watcher.watch.Payload.data()\" because the return value of \"org.elasticsearch.xpack.core.watcher.input.Input$Result.payload()\" is null"
      },

I tried to see the results of some variables by

Debug.explain()

but it seems that I cannot see them when I simulate the watcher from Kibana UI, as well as by executing it like this

POST _watcher/watch/my_watcher/_execute

Do you have any suggestions to migrate watchers to version 8?
Also debugging the result of some variables?
Thanks in advance

[Wave (Andrew Sullivan)]

Hi @mkaymak,

Would you be able be share an example of the watcher in question making sure to redact any confidential information please?