Cannot parse YAML file, (Line: 2, Col: 3, Idx: 6) - (Line: 2, Col: 3, Idx: 6): Exception during deserialization about yamldotnet

[EdwardCooke]

You're trying to deserialize a mapping into a string which isn't going to work. If instead you did this in your while loop:

var doc = yamlDeserializer.Deserialize<List<object>>(parser);
Console.WriteLine("## Document");
foreach (Dictionary<object, object> item in doc)
{
    foreach (var kvp in item)
    {
        Console.WriteLine("{0}: {1}", kvp.Key, kvp.Value);
    }
    Console.WriteLine("======");
}

It will result in:

## Document
name: Install certbot
tags: setup
community.general.snap: System.Collections.Generic.Dictionary`2[System.Object,System.Object]
======
name: Create symlink for Certbot binary
tags: setup
ansible.builtin.file: System.Collections.Generic.Dictionary`2[System.Object,System.Object]
become: true
======
name: Check if the certificate was already generated
tags: generate_cert
ansible.builtin.stat: System.Collections.Generic.Dictionary`2[System.Object,System.Object]
register: cert_fullchain_file
======
name: Generate certificate manually
tags: generate_cert
ansible.builtin.command: System.Collections.Generic.Dictionary`2[System.Object,System.Object]
when: not cert_fullchain_file.stat.exists
======

Since you're not specifying a class you'll need to reference everything as the expected datatype in the yaml, either string, List<object> or Dictionary<object, object>. Where object will generally be one of string, List<object>, or Dictionary<object, object>.

[rudolfolah]

amazing, that worked! thank you for the explanation. I've created a PR that updates the error message and adds a sample based on your reply.