Rollover issue when upgrading from ES5.6 to 6.8

I am receiving this issue below in ES6.8 when performing the same rollover function I have in ES5.6
{
"error": {
"root_cause": [
{
"type": "remote_transport_exception",
"reason": "[TrekrMZ][x.x.x.x:9300][indices:admin/rollover]"
}
],
"type": "illegal_argument_exception",
"reason": "unknown setting [analysis.analyzer.audmonnormalizer.char_filter] please check that any required plugins are installed, or check the breaking changes documentation for removed settings",
"suppressed": [
{
"type": "illegal_argument_exception",
"reason": "unknown setting [analysis.analyzer.audmonnormalizer.filter] please check that any required plugins are installed, or check the breaking changes documentation for removed settings"
},
{
"type": "illegal_argument_exception",
"reason": "unknown setting [analysis.analyzer.audmonnormalizer.type] please check that any required plugins are installed, or check the breaking changes documentation for removed settings"
},
{
"type": "illegal_argument_exception",
"reason": "unknown setting [number_of_replicas] did you mean [index.number_of_replicas]?"
},
{
"type": "illegal_argument_exception",
"reason": "unknown setting [number_of_shards] did you mean [index.number_of_shards]?"
}
]
},
"status": 400
}

I have this as part of the index definition:
"settings": {
"number_of_shards": 1,
"number_of_replicas": 1,
"analysis": {
"analyzer": {
"audmonnormalizer": {
"type": "custom",
"char_filter": ,
"filter": [
"lowercase",
"asciifolding"
]
}
}
}
}

What do you mean by rollover function?

POST /indexname/_rollover