Mapping error for rollover

Hi team,

I have a working ilm policy and template which rollsover the index. However, I cannot get the mappings to work in the policy, i a large list of errors such as:

index_template [my-alias] invalid, cause [Validation Failed: 1: unknown setting [index.mappings.properties.metricset.properties.name.type] please check that any required plugins are installed, or check the breaking changes documentation for removed settings;

Even though these index mappings work for the original index and my first test rollover index. My main question is, how can I get the rollover template to automatically put the mapping on the new index?

I got the mapping from the original index to go to the test rollover index by using:

POST /_reindex
{
  "source": {
    "index": "metric-amq"
  },
  "dest": {
    "index": "my-index-000001"
  }
}