Reindexing: unsupported parameters: [payloads : false]

[atom (Ammo)]

Hi

im currently upgrading our second ES instance from v2 to v5.
After upgrading i want to reindex my indexes in order to upgrade to v6.
Reindexing was successful in 30 of 41 indexes. Unfortunately, the rest 11 indexes are showing this error message during reindex:

{
  "statusCode": 400,
  "error": "Bad Request",
  "message": "Index mappings have errors.",
  "code": "ERR_MAPPER_PARSING_EXCEPTION",
  "root_cause": [
    {
      "type": "mapper_parsing_exception",
      "reason": "Mapping definition for [completion] has unsupported parameters:  [payloads : false]"
    }
  ],
  "type": "mapper_parsing_exception",
  "reason": "Failed to parse mapping [vacancy]: Mapping definition for [completion] has unsupported parameters:  [payloads : false]",
  "caused_by": {
    "type": "mapper_parsing_exception",
    "reason": "Mapping definition for [completion] has unsupported parameters:  [payloads : false]"
  },
  "reindexedIndexName": "test_vac-v5"
}

How can i solve this?
I have dumps of my analyzer, mapping and data. I tried importing my analyzer with elasticdump, after that i did an import of my mapping without payload but i cannot import my data. Do i need to modify it and if yes, how?
Or is there an easier way of doing this?

Thanks you so much in advance.
Regard,
Ahmet