Elastic Search - how to interpret this exception

This is the code I am running and it is missing custom analyzer name . And I got the following error

{
  "error": {
    "root_cause": [
      {
        "type": "settings_exception",
        "reason": "Failed to get setting group for [index.analysis.analyzer.] setting prefix and setting [index.analysis.analyzer.filter] because of a missing '.'"
      }
    ],
    "type": "settings_exception",
    "reason": "Failed to get setting group for [index.analysis.analyzer.] setting prefix and setting [index.analysis.analyzer.filter] because of a missing '.'"
  },
  "status": 500
}

Code snippet ( I am aware of what is the mistake, we need to supply custom analyzer name ). I would like know how to interpret the above exception to arrive to valid solution.

PUT myindex5
{
  "settings": {
    "analysis": {
      "char_filter": {
        "my_char_filter":{
          "type":"mapping",
          "mappings":["$ => dollar"]
        }
      },
      "filter": {
        "my_stopwords":{
          "type":"stop",
          "stopwords":["the"]
        }
      }, 
      "analyzer": {
        
         "type":"custom",
         "char_filter":["html_strip","my_char_filter"],
         "tokenizer":"standard",
         "filter":["lowercase","my_stopwords"]
       
      
      }
    }
  }
}