ReIndex API throws strict dynamic mapping exception

[paul1243]

Hi
When I try to re-index the .kibana index; I get an exception for all the documents:
Could someone please help me how to fix this error; since all my dashboards disappeared and have to restore the .kibana index.

Request:

POST _reindex
{
  "source": {
    "index": ".kibana-6"
  },
  "dest": {
    "index": ".kibana"
  }
}

Response:

{
  "took": 814,
  "timed_out": false,
  "total": 232,
  "updated": 0,
  "created": 4,
  "deleted": 0,
  "batches": 1,
  "version_conflicts": 0,
  "noops": 0,
  "retries": {
    "bulk": 0,
    "search": 0
  },
  "throttled_millis": 0,
  "requests_per_second": -1,
  "throttled_until_millis": 0,
  "failures": [
    {
      "index": ".kibana",
      "type": "doc",
      "id": "doc:visualization:aeb212e0-4c84-11e8-b3d7-01146121b73d",
      "cause": {
        "type": "strict_dynamic_mapping_exception",
        "reason": "mapping set to strict, dynamic introduction of [doc] within [doc] is not allowed"
      },
      "status": 400